Extract PT Story ID from provided PT URL

Created by: M3ssman

What is this Feature good for?

When using a SCM-Solution like GitLab or BitBucket, you can keep the proper Pivotaltracker URL like https://www.pivotaltracker.com/story/show/12345678 but still get the Intergration with Pivotaltracker, so you can browse the Repository an click directly to a corresponding Pivotaltracker Story. If the Commit-Message contains the whole PT-URL, it extracts the Story-ID and creates the usual PT-Service ID-Format from that. You still can use the "[#1234567]" Pattern in your Commits if you dont need the Backlink.

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