sqlalchemy: update version requirements

* Updated minimum and maximum version requirements for SQLAlchemy and
  SQLAlchemy-Utils.

* Fix compatibility problems with invenio.

Signed-off-by: Leonardo Rossi <leonardo.r@cern.ch>
see https://bitbucket.org/zzzeek/sqlalchemy/src/49f4d98c04f2224903e54e0eb3e3f901a27d1e38/lib/sqlalchemy/__init__.py?at=rel_0_9#cl-120