Storlets/Release Branch Creation

This is a temporary procedure till we are "Big Teneted"

1. In two different patches:
   1. pin the dependencies versions (Swift and Keystone) in tox.ini and in devstack localrc.sample
   2. Update CHANGELOG with the tag for the release, and the Release notes.
2. Once the above patches are approved create and push the above-mentioned release tag, this will initiate the PyPI jobs. Make sure your .gitconfig is up-to-date with e.g. the gpg signingkey entry.
   1. git tag -m "stable/newton tag" -s 0.3.0
   2. git push gerrit 0.3.0
3. Create the branch
   1. git checkout -b stable/newton
   2. git push gerrit stable/newton
4. On master undo the dependencies version pinning
5. If a backport is required checkout the branch and cherry-pick the backport commit:
   1. git checkout stable/newton
   2. git cherry-pick <commit>
   3. git review stable/newton