feat: add bitbucket merge commits to ignore list

[byCedric]

This PR is related to issue #60 and this comment.

Description

This adds two types of Bitbucket merge commits to the ignore list, which are generated by Bitbucket itself. It should allow all Bitbucket users to use the default message without the linter going berserk on these messages.

Motivation and Context

We at Peakfijn definitely want to use this tool. But since we are using Bitbucket all of our projects raises false positives on the default merge messages.

Usage examples

The following commands should now pass without failing.

$ echo "Merged in feature/facebook-friends-sync (pull request #8)" | commitlint
$ echo "Merged develop into feature/component-form-select-card" | commitlint

How Has This Been Tested?

I added these exact messages to the test file with a proper description about Bitbucket.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

[marionebl]

LGTM, merging as the Node.js 4 build appears to be stalled.

[marionebl]

Thanks!

[byCedric]

No problem, thanks for merging. The node 4 stall is related to the currently degraded performance, I'm experiencing it with other project too... Thanks again! 😄

[marionebl]

Released via 6.1.3

[byCedric]

Yes, currently implementing it in a future project at work! Thanks a lot, works like a charm