Add branch and sha1 to Jenkins webhook url.
Remove onpullrequestrescope handler from Pullrequesteventlistener

Remove onpullrequestrescope handler from Pullrequesteventlistener since
Repositorychangelistener will trigger changes on all branches.
Resolves #66.
Don't call webhook on branch delete
Temporary: Will be rewritten with configuration

- Deactivate triggering of webhook from opening and reopening of
  pull-requests.