Fixed pinned dependency versions
Fixed pinned dependency versions

These can cause real headaches if you have a different version of six or requests on your host machine.

This should fix the ``pkg_resources.DistributionNotFound`` error some people have been getting with the "wagtail start" command.
JoshBarr/wagtail,Pennebaker/wagtail,wagtail/wagtail,davecranwell/wagtail,torchbox/wagtail,serzans/wagtail,marctc/wagtail,mayapurmedia/wagtail,thenewguy/wagtail,WQuanfeng/wagtail,nilnvoid/wagtail,mikedingjan/wagtail,Klaudit/wagtail,m-sanders/wagtail,mjec/wagtail,Pennebaker/wagtail,chimeno/wagtail,nimasmi/wagtail,mjec/wagtail,kurtw/wagtail,davecranwell/wagtail,takeflight/wagtail,marctc/wagtail,Pennebaker/wagtail,janusnic/wagtail,chrxr/wagtail,taedori81/wagtail,mikedingjan/wagtail,rv816/wagtail,m-sanders/wagtail,wagtail/wagtail,kurtrwall/wagtail,rjsproxy/wagtail,jordij/wagtail,gogobook/wagtail,timorieber/wagtail,WQuanfeng/wagtail,gasman/wagtail,jordij/wagtail,kaedroho/wagtail,zerolab/wagtail,stevenewey/wagtail,mixxorz/wagtail,nimasmi/wagtail,mixxorz/wagtail,thenewguy/wagtail,darith27/wagtail,takeshineshiro/wagtail,janusnic/wagtail,serzans/wagtail,janusnic/wagtail,Toshakins/wagtail,nimasmi/wagtail,tangentlabs/wagtail,benjaoming/wagtail,kaedroho/wagtail,dresiu/wagtail,mikedingjan/wagtail,Toshakins/wagtail,dresiu/wagtail,KimGlazebrook/wagtail-experiment,nrsimha/wagtail,Tivix/wagtail,hamsterbacke23/wagtail,stevenewey/wagtail,hanpama/wagtail,jordij/wagtail,takeflight/wagtail,marctc/wagtail,kaedroho/wagtail,Tivix/wagtail,quru/wagtail,jnns/wagtail,chrxr/wagtail,takeshineshiro/wagtail,FlipperPA/wagtail,thenewguy/wagtail,taedori81/wagtail,jnns/wagtail,inonit/wagtail,rsalmaso/wagtail,mikedingjan/wagtail,chimeno/wagtail,Toshakins/wagtail,gogobook/wagtail,kurtrwall/wagtail,darith27/wagtail,inonit/wagtail,torchbox/wagtail,rjsproxy/wagtail,mayapurmedia/wagtail,m-sanders/wagtail,rsalmaso/wagtail,bjesus/wagtail,wagtail/wagtail,gasman/wagtail,nutztherookie/wagtail,takeshineshiro/wagtail,taedori81/wagtail,kaedroho/wagtail,quru/wagtail,chrxr/wagtail,FlipperPA/wagtail,gasman/wagtail,gasman/wagtail,tangentlabs/wagtail,bjesus/wagtail,thenewguy/wagtail,gogobook/wagtail,mixxorz/wagtail,mixxorz/wagtail,mixxorz/wagtail,janusnic/wagtail,nrsimha/wagtail,jorge-marques/wagtail,hamsterbacke23/wagtail,chimeno/wagtail,quru/wagtail,iho/wagtail,serzans/wagtail,jordij/wagtail,nealtodd/wagtail,mephizzle/wagtail,JoshBarr/wagtail,wagtail/wagtail,hamsterbacke23/wagtail,kurtw/wagtail,nutztherookie/wagtail,kurtw/wagtail,nutztherookie/wagtail,Tivix/wagtail,jorge-marques/wagtail,KimGlazebrook/wagtail-experiment,iansprice/wagtail,JoshBarr/wagtail,inonit/wagtail,kurtrwall/wagtail,Pennebaker/wagtail,nrsimha/wagtail,jnns/wagtail,gasman/wagtail,taedori81/wagtail,benjaoming/wagtail,takeflight/wagtail,nealtodd/wagtail,iansprice/wagtail,mephizzle/wagtail,KimGlazebrook/wagtail-experiment,quru/wagtail,m-sanders/wagtail,rv816/wagtail,darith27/wagtail,nutztherookie/wagtail,JoshBarr/wagtail,iansprice/wagtail,gogobook/wagtail,rsalmaso/wagtail,iansprice/wagtail,nealtodd/wagtail,rsalmaso/wagtail,darith27/wagtail,benjaoming/wagtail,Klaudit/wagtail,bjesus/wagtail,mephizzle/wagtail,Klaudit/wagtail,jorge-marques/wagtail,jorge-marques/wagtail,takeshineshiro/wagtail,benjaoming/wagtail,zerolab/wagtail,kurtrwall/wagtail,Tivix/wagtail,FlipperPA/wagtail,dresiu/wagtail,jnns/wagtail,davecranwell/wagtail,mjec/wagtail,mayapurmedia/wagtail,zerolab/wagtail,timorieber/wagtail,dresiu/wagtail,mephizzle/wagtail,takeflight/wagtail,tangentlabs/wagtail,stevenewey/wagtail,rv816/wagtail,FlipperPA/wagtail,hanpama/wagtail,nilnvoid/wagtail,inonit/wagtail,chimeno/wagtail,stevenewey/wagtail,torchbox/wagtail,tangentlabs/wagtail,taedori81/wagtail,timorieber/wagtail,timorieber/wagtail,Toshakins/wagtail,mjec/wagtail,rjsproxy/wagtail,iho/wagtail,hamsterbacke23/wagtail,wagtail/wagtail,dresiu/wagtail,WQuanfeng/wagtail,KimGlazebrook/wagtail-experiment,nealtodd/wagtail,rsalmaso/wagtail,iho/wagtail,serzans/wagtail,marctc/wagtail,thenewguy/wagtail,nilnvoid/wagtail,nilnvoid/wagtail,hanpama/wagtail,nimasmi/wagtail,davecranwell/wagtail,jorge-marques/wagtail,bjesus/wagtail,kaedroho/wagtail,iho/wagtail,chimeno/wagtail,kurtw/wagtail,zerolab/wagtail,rjsproxy/wagtail,torchbox/wagtail,mayapurmedia/wagtail,rv816/wagtail,hanpama/wagtail,chrxr/wagtail,WQuanfeng/wagtail,nrsimha/wagtail,zerolab/wagtail,Klaudit/wagtail