Revert https://github.com/GreenGroup/RMG-Py/commit/475caef57916e4c30b53e9c6bf80f0e1e4adbb81 and move databaseTest.py back to parent folder.

Make travis build in RMG-Py only run the RMG-Py function unittests but not
the database test.  Have the database test be run in the RMG-database
repository's travis build.