added scoped session test independent of Session.mapper test
added scoped session test independent of Session.mapper test

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