Update oslo-incubator timeutils module

Changes -
 * Avoid TypeError in is_older_than, is_newer_than

Change-Id: Ia600547f2564cdd93c464f14f753dc1a6bfbfa89
Update oslo-incubator db.sqlalchemy module

Changes -
 * Use hacking import_exceptions for gettextutils._
 * Add docstring for exception handlers of session
 * Removal of _REPOSITORY global variable.
 * Remove string.lowercase usage
 * Database hook enabling traditional mode at MySQL
 * Replace xrange in for loop with range
 * SQLAlchemy error patterns improved
 * Remove unused import
 * Correct invalid docstrings
 * Remove start index 0 in range()
 * Make _extra_keys a property of ModelBase

Change-Id: If0ecdeb5fefcef36bd14af5a46481cacf2580239
Update oslo-incubator excutils module

Changes -
 * Use hacking import_exceptions for gettextutils._
 * Correct invalid docstrings

Change-Id: I0dad350439e49513ed1d26800b11ac51d61e0343