Update completer tests with new region
Update CloudTrail customization call format.

Updates the AWS CloudTrail create-subscription and update-subscription
customizations to use the latest CloudTrail API, which includes changes
in the way parameters are passed into the CreateTrail and UpdateTrail
operations.
Remove str() call from part_number args

The model now defines these properly as ints.
Add banner for new region
Update changelog with latest features
Bumping version to 1.2.9
Merge branch 'release-1.2.9' into develop

* release-1.2.9:
  Bumping version to 1.2.9
  Update changelog with latest features
  Add banner for new region
  Remove str() call from part_number args
  Update CloudTrail customization call format.
  Update completer tests with new region
Merge remote-tracking branch 'upstream/develop' into develop