Fixed group calls to work with driver's new API
Fixed group calls to work with driver's new API

For more info on the change to the group method, see:
https://github.com/mongodb/mongo-ruby-driver/commit/65f59ba2d643954327bd1acd94ac8209ecdbc0eb

FestivalBobcats/mongoid,xinuc/mongoid,bigbenli/mongoid,semaperepelitsa/mongoid,joshleitzel/mongoid,skiz/mongoid,andreychernih/mongoid,canvas-drw/mongoid,HeeL/mongoid-1,narutosanjiv/mongoid,hookercookerman/mongoid,skiz/mongoid,britto/mongoid,zaithottakath/mongoid,marcweil/mongoid,cmartyn/mongoid,infiverve/mongoid,stevebartholomew/mongoid,mongodb/mongoid,brynary/mongoid,nagachika/mongoid,abscondment/mongoid,lowang/mongoid,uranazo/mongoid,tvon/mongoid,simi/mongoid,alexrothenberg/mongoid,jasl/mongoid,Houdini/mongoid,ealdent/mongoid,spiegela/mongoid,ealdent/mongoid,maxd/mongoid,joshsoftware/mongoid,hfwang/mongoid,jmaicher/mongoid,rpocklin/mongoid,slbug/mongoid,zanker/mongoid,shingara/mongoid,tetsuo692/mongoid,wuboy0307/mongoid,kentaroi/mongoid,akirasosa/mongoid,zBMNForks/mongoid,fbernier/mongoid,SumeruSoftware/mongoid,skyeagle/mongoid,mongodb/mongoid,tanordheim/mongoid,kentaroi/mongoid,priyaaank/mongoid,kevinmarvin/mongoid,mhs/mongoid,dcu/mongoid,Welovroi/mongoid,johnnyshields/mongoid,mitio/mongoid,rafaelgaspar/mongoid,mhs/mongoid,leedo/mongoid,imomoisoft/mongoid,tagliala/mongoid,praecipula/mongoid,neerfri/mongoid,stellard/mongoid,stnguyen/mongoid,niedhui/mongoid,tolsen/mongoid,uranazo/mongoid,camallen/mongoid,flexoid/mongoid,hbakhtiyor/mongoid,niedhui/mongoid,jamesalmond/mongoid,ryanong/mongoid,socialreferral/mongoid,trmmy/mongoid,rymai/mongoid,genexp/mongoid,bigbenli/mongoid,rmm5t/mongoid,potatosalad/mongoid,lackac/mongoid,jbrien/mongoid,brettgoulder/mongoid-1,mysociety/mongoid,cavneb/mongoid,ginty/mongoid,sivagollapalli/mongoid,captain-lucas/mongoid,jiren/mongoid,dustinwatson/mongoid,caiofilipini/mongoid,msaffitz/mongoid,estolfo/mongoid,jakcharlton/mongoid,luxerama/mongoid,drobune/mongoid,balauru/mongoid,likealittle/mongoid,sukeerthiadiga/mongoid,luxerama/mongoid,subhashb/mongoid,matbox/mongoid,nicolasblanco/mongoid,cpuguy83/mongoid,drobune/mongoid,nextmat/mongoid,ElvinEfendi/mongoid,jeffreyiacono/mongoid,joelcogen/mongoid,cpuguy83/mongoid,anuprit/mongoid,HRNewMedia/mongoid,CIRCUITLLC/mongoid,rosylilly/mongoid,Flameeyes/mongoid,ahoward/mongoid,greggroth/mongoid,Sharevari-Inc/mongoid,charliehq/mongoid,nusco/mongoid,sserdyuk/mongoid,jpfuentes2/mongoid,cmartyn/mongoid,jetthoughts/mongoid,jtescher/mongoid,iGoDigital-LLC/mongoid,koraktor/mongoid,jseibert/mongoid,Winslett/mongoid,timgluz/mongoid,jordoh/mongoid,xentek/mongoid,amw/mongoid,500px/mongoid,teaforthecat/mongoid,icambron/mongoid,X0nic/mongoid,korishev/mongoid,4pcbr/mongoid,jasl/mongoid,krasnoukhov/mongoid,msaffitz/mongoid,joshleitzel/mongoid,evendis/mongoid,bjori/mongoid,karmakaze/mongoid,icambron/mongoid,incorvia/mongoid,hxx/mongoid,Aupajo/mongoid-1,Zhomart/mongoid,mzsanford/mongoid,wyattisimo/mongoid,tolsen/mongoid,zenjoy/mongoid,bobbytables/mongoid,robwil/mongoid,Spaceghost/mongoid,demarque/mongoid,aileron/mongoid,stnguyen/mongoid,aleksclark/mongoid,charliehq/mongoid,caiofilipini/mongoid,kayakyakr/mongoid,matsimitsu/mongoid,krasnoukhov/mongoid,DanielVartanov/mongoid,haihappen/mongoid,fujimura/mongoid,rinmu/mongoid,drfeelngood/mongoid,evansagge/mongoid,alexandru-calinoiu/mongoid,Spaceghost/mongoid,sikachu/mongoid,blackxored/mongoid,mzsanford/mongoid,stevebartholomew/mongoid,jtescher/mongoid,Numerico/mongoid,Subskii/mongoid,leemhenson/mongoid,rubrikkfabrikken/mongoid,mitijain123/mongoid,javmorin/mongoid,bjori/mongoid,simi/mongoid,leozhang37/mongoid,razum2um/mongoid,jakcharlton/mongoid,yuuna/mongoid,genexp/mongoid,korishev/mongoid,jordelver/mongoid,mongodb/mongoid,codedogfish/mongoid,cleishm/mongoid,xinuc/mongoid,praecipula/mongoid,moretea/mongoid,arnkorty/mongoid,uniiverse/mongoid,derekharmel/mongoid,narutosanjiv/mongoid,rafaelgaspar/mongoid,absperf/mongoid,dnd/mongoid,socialreferral/mongoid,nextmat/mongoid,getaroom/mongoid,akreiling/mongoid,dnd/mongoid,sepastian/mongoid,aileron/mongoid,gicappa/mongoid,elia/mongoid,Numerico/mongoid,envylabs/mongoid,Welovroi/mongoid,bdmac/mongoid,Exoth/mongoid,robotmay/mongoid,gregmolnar/mongoid,tagliala/mongoid,Sharevari-Inc/mongoid,crealytics/mongoid,grossws/mongoid,cncolder/mongoid,dlt/mongoid,parov/mongoid,maxd/mongoid,crealytics/mongoid,sepastian/mongoid,ryanong/mongoid,JonRowe/mongoid,anuprit/mongoid,pkieltyka/mongoid,dblock/mongoid,nagachika/mongoid,Exoth/mongoid,shotoso/mongoid,toppan-forms/mongoid,robinst/mongoid,Tickaroo/mongoid2,alexrothenberg/mongoid,bearded/mongoid,iboard/mongoid-1,matsimitsu/mongoid,hubertlepicki/mongoid,skippy/mongoid,Azzurrio/mongoid,cao7113/mongoid,jeffreyiacono/mongoid,mitijain123/mongoid,kostyantyn/mongoid,brettgoulder/mongoid-1,christiannelson/mongoid,jeyb/mongoid,jetthoughts/mongoid,jbrien/mongoid,rpocklin/mongoid,mongoid/mongoid,kevinmarvin/mongoid,notxarb/mongoid,jstrocel/mongoid,tombruijn/mongoid,tricknotes/mongoid,dannguyen/mongoid,afeld/mongoid,jpfuentes2/mongoid,kcdragon/mongoid,EqualMedia/mongoid,derickbailey/mongoid,florent/mongoid,gregory-m/mongoid,arnkorty/mongoid,tengine/mongoid,hashrocketeer/mongoid,kryzhovnik/mongoid,abezzub/mongoid,canavese/mongoid,77Agency/mongoid,captain-lucas/mongoid,nfo/mongoid,neerfri/mongoid,4pcbr/mongoid,robwil/mongoid,wuboy0307/mongoid,joneslee85/mongoid,codedogfish/mongoid,subhashb/mongoid,shotoso/mongoid,etomic/mongoid,zenjoy/mongoid,mathieuravaux/mongoid,matadon/mongoid,imomoisoft/mongoid,stellard/mongoid,chetan/mongoid,500px/mongoid,crowdtap/mongoid,flada-auxv/mongoid,greggroth/mongoid,mikerobe/mongoid,gregmolnar/mongoid,iGoDigital-LLC/mongoid,LastStar/mongoid,notxarb/mongoid,mschulkind/mongoid,CIRCUITLLC/mongoid,Winslett/mongoid,jamesalmond/mongoid,toppan-forms/mongoid,nviennot/mongoid,johnnyshields/mongoid,justinko/mongoid,tombruijn/mongoid,dbkbali/mongoid,gullitmiranda/mongoid,mash-ltd/mongoid,eddanger/mongoid,abscondment/mongoid,itbakery/mongoid,derekharmel/mongoid,christiannelson/mongoid,sporkd/mongoid,voldy/mongoid,irakli-janiashvili/mongoid,mschulkind/mongoid,pkieltyka/mongoid,manuelmorales/mongoid,kslazarev/mongoid,kslazarev/mongoid,mash-ltd/mongoid,Speakol/mongoid,adyard/mongoid,cao7113/mongoid,mongoid/mongoid,gregory-m/mongoid,alexandru-calinoiu/mongoid,jordelver/mongoid,cgriego/mongoid,lawrencecurtis/mongoid,sideci-sample/sideci-sample-mongoid,sevos/mongoid,MadRabbit/mongoid,incorvia/mongoid,aj0strow/mongoid,johnny-miyake/mongoid,ErisExchange/mongoid,razum2um/mongoid,fortnightlabs/mongoid,afeld/mongoid,byroot/mongoid,hashrocketeer/mongoid,atomical/mongoid,karmakaze/mongoid,cmpolis/mongoid,kcdragon/mongoid,mgolovnia/mongoid,kay-kim/mongoid,dsachitano/mongoid,albus522/mongoid,i0rek/mongoid,sukeerthiadiga/mongoid,asaaki/mongoid,jstrocel/mongoid,sideci-sample/sideci-sample-mongoid,nusco/mongoid,DouweM/mongoid,loginx/mongoid,franc/mongoid,paulrosania/mongoid,voldy/mongoid,Shop2market/mongoid,mgartner/mongoid,akreiling/mongoid,rafaelfranca/mongoid,mysociety/mongoid,Speakol/mongoid,jordoh/mongoid,77Agency/mongoid,ginty/mongoid,blt04/mongoid,KoanHealth/mongoid,X0nic/mongoid,Azzurrio/mongoid,franc/mongoid,hubertlepicki/mongoid,kuruma-gs/mongoid,cgriego/mongoid,romanbsd/mongoid,cncolder/mongoid,sujal/mongoid,joshsoftware/mongoid,chriseppstein/mongoid,fortnightlabs/mongoid,asaaki/mongoid,freerange/mongoid,iamnader/mongoid-2,derickbailey/mongoid,aj0strow/mongoid,jonhyman/mongoid,eddanger/mongoid,rogerz42892/mongoid,trmmy/mongoid,nullstyle/mongoid,kostyantyn/mongoid,aagrawal2001/mongoid,timgluz/mongoid,janroesner/mongoid,potatosalad/mongoid,skippy/mongoid,elia/mongoid,jeyb/mongoid,arunagw/mongoid,bobbytables/mongoid,manikandan-kandasamy/mongoid,kayakyakr/mongoid,nviennot/mongoid,lucasas/mongoid,piotrj/mongoid,tzar/mongoid,asantamar/mongoid,sserdyuk/mongoid,mulder/mongoid,colinyoung/mongoid,sevos/mongoid,rogerz42892/mongoid,evendis/mongoid,jim/mongoid,hxx/mongoid,mehowte/mongoid,idesaku/mongoid,railsjedi/mongoid,grimen/mongoid,Codas/mongoid,jmaicher/mongoid,tetsuo692/mongoid,sporkd/mongoid,KoanHealth/mongoid,grossws/mongoid,rosylilly/mongoid,itbakery/mongoid,schnittchen/mongoid,rmm5t/mongoid,dakatsuka/mongoid,moretea/mongoid,rebelhold/mongoid,ahoward/mongoid,flexoid/mongoid,ElvinEfendi/mongoid,mattconnolly/mongoid,joelcogen/mongoid,jim/mongoid,rinmu/mongoid,astjohn/mongoid,eljojo/mongoid,env0der/mongoid,cavneb/mongoid,balauru/mongoid,PerfectMemory/mongoid,travis-repos/mongoid,britto/mongoid,dferdian/mongoid,estolfo/mongoid,lawrencecurtis/mongoid,mehowte/mongoid,canavese/mongoid,colinyoung/mongoid,LastStar/mongoid,mgartner/mongoid,dsachitano/mongoid,canvas-drw/mongoid,nickhoffman/mongoid,apptentive-engineering/mongoid,capnregex/mongoid,spiegela/mongoid,andreychernih/mongoid,apptentive-engineering/mongoid,PerfectMemory/mongoid,gicappa/mongoid,herimedia/mongoid,janroesner/mongoid,evansagge/mongoid,zBMNForks/mongoid,cjab/mongoid,chriseppstein/mongoid,dcu/mongoid,blackxored/mongoid,ebeigarts/mongoid,slbug/mongoid,hookercookerman/mongoid,dlt/mongoid,ches/mongoid,nickhoffman/mongoid,MSNexploder/mongoid,etomic/mongoid,adyard/mongoid,ganlron/mongoid,paulrosania/mongoid,codedmart/mongoid,brynary/mongoid,marcweil/mongoid,hbakhtiyor/mongoid,hadees/mongoid,flada-auxv/mongoid,joneslee85/mongoid,kryzhovnik/mongoid,bdmac/mongoid,bencrouse/mongoid,MSNexploder/mongoid,aleksclark/mongoid,hfwang/mongoid,bearded/mongoid,nullstyle/mongoid,codedmart/mongoid,crowdtap/mongoid,camallen/mongoid,jasonsydes/mongoid,goshakkk/mongoid,lackac/mongoid,kuadrosx/mongoid,shingara/mongoid,railsjedi/mongoid,herimedia/mongoid,javmorin/mongoid,idesaku/mongoid,jonhyman/mongoid,irakli-janiashvili/mongoid,asantamar/mongoid,tzar/mongoid,matbox/mongoid,DanielVartanov/mongoid,cleishm/mongoid,sikachu/mongoid,ErisExchange/mongoid,akm/mongoid,gullitmiranda/mongoid,rubrikkfabrikken/mongoid,infiverve/mongoid,glebtv/mongoid,eljojo/mongoid,parov/mongoid,fbernier/mongoid,amw/mongoid,aagrawal2001/mongoid,drfeelngood/mongoid,FestivalBobcats/mongoid,zaithottakath/mongoid,haihappen/mongoid,envylabs/mongoid,manikandan-kandasamy/mongoid,SumeruSoftware/mongoid,demarque/mongoid,mulder/mongoid,Subskii/mongoid,akirasosa/mongoid,fredjean/mongoid,kay-kim/mongoid,ono/mongoid,Zhomart/mongoid,mathieuravaux/mongoid,leedo/mongoid,Codas/mongoid,lowang/mongoid,uniiverse/mongoid,manuelmorales/mongoid,snapfish-soma/mongoid,tricknotes/mongoid,akm/mongoid,johnny-miyake/mongoid,tanordheim/mongoid,nfo/mongoid,dustinwatson/mongoid,florent/mongoid,mattconnolly/mongoid,kuadrosx/mongoid,malditogeek/mongoid,chetan/mongoid,alex-klepa/mongoid,JonRowe/mongoid,dbkbali/mongoid,goshakkk/mongoid,justinko/mongoid,arunagw/mongoid,teaforthecat/mongoid,cmpolis/mongoid,dannguyen/mongoid,mikerobe/mongoid,atomical/mongoid,HeeL/mongoid-1,theirishpenguin/mongoid,EqualMedia/mongoid,tvon/mongoid,jseibert/mongoid,Empact/mongoid,bencrouse/mongoid,fredjean/mongoid,lucasas/mongoid,ebeigarts/mongoid,wyattisimo/mongoid,ches/mongoid,sivagollapalli/mongoid,malditogeek/mongoid,kuruma-gs/mongoid,jetheredge/mongoid,zanker/mongoid,glebtv/mongoid,jonasschneider/mongoid,xentek/mongoid,dferdian/mongoid,ganlron/mongoid,freerange/mongoid,hadees/mongoid,rafaelfranca/mongoid,travis-repos/mongoid,yuuna/mongoid,abezzub/mongoid