updated toolset for HTTP::Tiny
Added test for fetching pg backend
Added support for using postgression and testpg backends
Added postgression and testpg(Test::PostgreSQL) backend support for
postgresql
Added unit test for both of these backends.
splitted the Test::Chado specific tests for backend into its own file
acitvated test for testpg backend in travis
Cleaned up the doc of Test::Chado
activated postgression backend testing
Merge branch 'feature/postgression-backend' into develop