This implements the following changes:
- The sources-branch-updater script will only update SHA's/tags
for OpenStack roles. This is primarily for usage in stable
branches where external roles must not be changed after release.
- The script will no longer update the *requirements.txt files.
These files are managed by the OpenStack Global Requirements
management process.
- The pins for pip, setuptools and wheels are now set in the
global-requirement-pins.txt file in order to ensure that it
takes precedence in the repo build process above all other
requirements.
- The order of the requirements.txt file has been changed to ensure
that pip, setuptools and wheels is installed first whenever the
requirements.txt file is used.
- The pin comment has been removed from the requirements.txt file
as it no longer applies..
Change-Id: Ib98e63153ace7f02b9bbce878aa67fbdddd784b6
60bad86d54