Aws hook

Created by: suppamax

New flow, to overcome the issue of getting AWS credentials from a flow started from a fork:

• when a PR is created, check_target_on_pr verifies that the target branch is dev (the repo owner can decide to merge anyway)
• when a push to dev is done by an OpenHW staff member (Mike, Florian or Davide), AWS CodeBuild is started
• upon successful completion of the AWS CodeBuild job, dev is merged to master

Note: requires a dev branch