Set boto minimum version

For supporting the S3 multipart upload in glance,
set boto minimum version to 2.12.0.

Implements: blueprint s3-multi-part-upload
Change-Id: Id57a3887256a665455fd83d3e8e752a28c5e7659
Add sphinxcontrib-docbookrestapi

Ceilometer would like to use this piece of software to generate its
documentation on api-site.openstack.org.

Change-Id: Iaa84962378eb1cee9edaccd1ba50b6ad020e1d2a
Add oslo-incubator to automatic update

Change-Id: If422761221a21cfc0da08bd905c8e88f08a8fcce
Merge "Set boto minimum version"
Merge "Add oslo-incubator to automatic update"
Merge "Add sphinxcontrib-docbookrestapi"
Align projects list with mirror-needing projects

If projects.txt is going to be the basis for select-mirror in the
gate, we should also list projects in projects.txt that need to be
constrained by the mirror for their testing. In order to do that, we
need to not try to unconditionally update setup.py, since devstack and
devstack-gate do not have it.

openstack/requirements itself also does not use the mirror, so remove
it from the list.

Change-Id: Iea33e8f4d5453bf413f3d479b85eaed99938b302