tests against sqlalchemy main test suite

This basically has two parts:

1. Add all the requirements that are used in the main tests suite
2. Fix a bunch of bugs in the sqlalchemy adapter
3. Add support to the sqlalchemy adapter that the sql layer now supports
Good catch, it was actually a side effect of copying the default requirements into our requirements. There were a bunch of duplicate declarations, so the microseconds we're open and then closed later. All duplicates have been removed.