Pin SQLAlchemy to 0.7.x
Pin SQLAlchemy to 0.7.x

0.7.10 has been released and is compatible with 0.7.x. Instead
of pinning to 0.7.9, simply pin to 0.7.x to avoid SQLAlchemy 0.8

Change-Id: Iea57598698b4faf906e82a2974497221d07f4d16

openstack-dev/hacking,zancas/hacking,hyakuhei/cleantox,emonty/oslo-hacking,hyakuhei/cleantox,openstack-dev/hacking,zancas/hacking,emonty/oslo-hacking