Update Heroku config in README
Update Heroku config in README

mongolab free plan is now called "sandbox"
linki/errbit,alphagov/errbit,wombatsecurity/errbit,espnbr/errbit,damau/errbit,otzy007/errbit,deskrock/errbit,iFixit/errbit,Undev/errbit,rightscale/errbit_old,dwilkie/errbit,errbit/errbit,shyftplan/errbit,Cloud-Temple/errbit,jordoh/errbit,damau/errbit,rightscale/errbit_old,rud/errbit,deskrock/errbit,mikk150/errbit,dwilkie/errbit,Talentee/errbit,sinrutina/errbit,diowa/errbit,peertransfer/errbit,alphagov/errbit,griff/errbit,jjosten/errbit,KomalDhanwani/errorinspector,Promptus/errbit,fireho/errbit,bonanza-market/errbit,espnbr/errbit,fireho/errbit,notch8/errbit,francetv/errbit,dwilkie/errbit,felixbuenemann/errbit,fxposter/errbit,mak-it/errbit,threatsim/errbit,KomalDhanwani/errorinspector,arrowcircle/errbit,micred/errbit,arrowcircle/errbit,vinco/errbit,Undev/errbit,vinco/errbit,denyago/errbit,CarlosCD/errbit,14113/errbit-1,aurels/errbit,alphagov/errbit,subvisual/errbit,Strnadj/errbit,threatsim/errbit,appdate/errbit,cph/errbit,Cloud-Temple/errbit,diowa/errbit,smonsalve/lacasona-errbit,14113/errbit-1,errbit/errbit,Undev/errbit,jaronkk/errbit,jaronkk/errbit,huangxiangdan/errbit,rightscale/errbit,14113/errbit-1,salemove/errbit,linki/errbit,concordia-publishing-house/errbit,arrowcircle/errbit,bengler/errbit,Cloud-Temple/errbit,otzy007/errbit,projectdx/errbit,pallan/errbit,lucianosousa/errbit,Gratzi/pegg-errors,salemove/errbit,accessd/errbit,griff/errbit,pandora2000/errbit,cph/errbit,Talentee/errbit,Talentee/errbit,deskrock/errbit,rightscale/errbit_old,mikk150/errbit,12spokes/errbit,ninech/errbit,diowa/errbit,mikk150/errbit,14113/errbit-1,3zcurdia/errbit,joshuaswilcox/Errbitstrap,steveyken/errbit,sideci-sample/sideci-sample-errbit,bengler/errbit,openSUSE/errbit,peertransfer/errbit,wombatsecurity/errbit,accessd/errbit,shyftplan/errbit,joshuaswilcox/Errbitstrap,PeggApp/pegg-errors,concordia-publishing-house/errbit,shivanibhanwal/errbit,huangxiangdan/errbit,stevecrozz/errbit,stevecrozz/errbit,3zcurdia/errbit,errbit/errbit,jaronkk/errbit,rud/errbit,ZeusWPI/errbit,burningpony/errbit,appdate/errbit,cph/errbit,rud/errbit,accessd/errbit,appdate/errbit,bonanza-market/errbit,Promptus/errbit,threatsim/errbit,aurels/errbit,assetricity/errbit,gravity-platform/errbit,wombatsecurity/errbit,notch8/errbit,francetv/errbit,startdatelabs/errbit,mvz/errbit,denyago/errbit,smonsalve/lacasona-errbit,Stackato-Apps/errbit,PeggApp/pegg-errors,Talentee/errbit,arrowcircle/errbit,joshuaswilcox/Errbitstrap,cognoa/errbit,deskrock/errbit,alphagov/errbit,ndlib/errbit,micred/errbit,Undev/errbit,zenjoy/errbit,jjosten/errbit,Promptus/errbit,notch8/errbit,burningpony/errbit,fxposter/errbit,Stackato-Apps/errbit,ninech/errbit,denyago/errbit,francetv/errbit,fusco/errbit,ndlib/errbit,sinrutina/errbit,cognoa/errbit,subvisual/errbit,assetricity/errbit,fxposter/errbit,disvelop/errbit,bonanza-market/errbit,Gratzi/pegg-errors,rightscale/errbit,mvz/errbit,stevecrozz/errbit,cph/errbit,fusco/errbit,openSUSE/errbit,PeggApp/pegg-errors,projectdx/errbit,startdatelabs/errbit,denyago/errbit,Strnadj/errbit,ninech/errbit,lucianosousa/errbit,wombatsecurity/errbit,jordoh/errbit,chautoni/mingle-errbit,sideci-sample/sideci-sample-errbit,shivanibhanwal/errbit,gravity-platform/errbit,subvisual/errbit,felixbuenemann/errbit,fusco/errbit,pandora2000/errbit,Stackato-Apps/errbit,cognoa/errbit,damau/errbit,salemove/errbit,3zcurdia/errbit,bengler/errbit,shivanibhanwal/errbit,projectdx/errbit,gravity-platform/errbit,subvisual/errbit,burningpony/errbit,Gratzi/pegg-errors,jjosten/errbit,chautoni/mingle-errbit,sinrutina/errbit,threatsim/errbit,disvelop/errbit,pandora2000/errbit,ZeusWPI/errbit,openSUSE/errbit,mak-it/errbit,chautoni/mingle-errbit,rightscale/errbit,zenjoy/errbit,12spokes/errbit,ZeusWPI/errbit,peertransfer/errbit,disvelop/errbit,shyftplan/errbit,concordia-publishing-house/errbit,huangxiangdan/errbit,lucianosousa/errbit,mak-it/errbit,CarlosCD/errbit,steveyken/errbit,griff/errbit,rightscale/errbit_old,vinco/errbit,CarlosCD/errbit,12spokes/errbit,KomalDhanwani/errorinspector,linki/errbit,mvz/errbit,startdatelabs/errbit,pallan/errbit,Strnadj/errbit,accessd/errbit,steveyken/errbit,micred/errbit,assetricity/errbit,otzy007/errbit,iFixit/errbit,ndlib/errbit,fireho/errbit,felixbuenemann/errbit,concordia-publishing-house/errbit,jordoh/errbit,iFixit/errbit,espnbr/errbit