Include psycopg2cffi in dialect docs
Include psycopg2cffi in dialect docs

hsum/sqlalchemy,dstufft/sqlalchemy,davidjb/sqlalchemy,epa/sqlalchemy,robin900/sqlalchemy,EvaSDK/sqlalchemy,robin900/sqlalchemy,davidjb/sqlalchemy,pdufour/sqlalchemy,wfxiang08/sqlalchemy,monetate/sqlalchemy,elelianghh/sqlalchemy,Akrog/sqlalchemy,epa/sqlalchemy,j5int/sqlalchemy,wfxiang08/sqlalchemy,brianv0/sqlalchemy,wujuguang/sqlalchemy,bootandy/sqlalchemy,bdupharm/sqlalchemy,davidfraser/sqlalchemy,pdufour/sqlalchemy,EvaSDK/sqlalchemy,wujuguang/sqlalchemy,Akrog/sqlalchemy,276361270/sqlalchemy,ThiefMaster/sqlalchemy,elelianghh/sqlalchemy,dstufft/sqlalchemy,bdupharm/sqlalchemy,olemis/sqlalchemy,inspirehep/sqlalchemy,WinterNis/sqlalchemy,sandan/sqlalchemy,j5int/sqlalchemy,ThiefMaster/sqlalchemy,hsum/sqlalchemy,sandan/sqlalchemy,itkovian/sqlalchemy,halfcrazy/sqlalchemy,graingert/sqlalchemy,itkovian/sqlalchemy,davidfraser/sqlalchemy,sqlalchemy/sqlalchemy,276361270/sqlalchemy,WinterNis/sqlalchemy,inspirehep/sqlalchemy,olemis/sqlalchemy,brianv0/sqlalchemy,bootandy/sqlalchemy,halfcrazy/sqlalchemy,monetate/sqlalchemy,graingert/sqlalchemy,zzzeek/sqlalchemy