Remove branches merge commits are not identified as valid merge commits

[johnsimons]

If we use github to merge a PR from a hotfix branch to master, GitVersion complaints that:

The head of master should always be a merge commit if you follow gitflow. Please create one or work around this by tagging the commit with SemVer compatible Id.

I think this should also be supported.

So the problem is that when Github does the merge, it uses the remote branch name eg Particular/hotfix-4.6.2, and GitVersion expects the merge to occur from a local branch.

[JakeGinnivan]

Yeah, it should always be a merge commit. But sometimes people might want to commit release notes or something additional quickly on master before the release, I don't think we should prevent this

[johnsimons]

And it is a merge commit, github uses the following:
git merge --no-ff branchname
this command produces a merge commit.

[johnsimons]

The following commit message is not identified as a merge commit:
Merge branch 'hotfix-4.2.2' into support-4.2

[JakeGinnivan]

Verified this is fixed in 3.0