Backport-action 0.0.4

Features

• support triggering the action using a comment #14
• support custom label_pattern #42
• improved error messages #25 #31 #47

Testing

• added acceptance tests for the internal backport.sh script #10
• enforce committer name/email in tests #13

Other

• improved README, including better workflow examples #40
• added dependabot #15
• updated dependencies to latest available