(WIP) Run rdopkg reqcheck on every RDO package

[hguemar]

Upstream froze requirements for Pike, so it's now the right moment to refresh our packaging requirements.

• [ ] nova
• [ ] cinder
• [ ] glance
• [ ] ironic
• [ ] keystone
• [ ] sahara
• [ ] trove
• [ ] zaqar

[snecklifter]

@hguemar this is still WIP?