Update auto-changelog

[cookpete]

Checklist

• Have you linked to relevant open issues?: No (there is no relevant issue)
• I agree for this to be covered by the Velocity license?: Yes

Please describe this Pull Request in as much detail as possible:

The format of the current changelog is a bit off as it includes multiple lines of the commit message, resulting in lines where the fixes are repeated:

• Grab Promise in a try/catch Fixes IE compatibility broken. Promise is undefined. [v2.0.3] #875 #875

The problem is that auto-changelog uses git log behind the scenes, which assumes that the commit subject and body are separated by two newlines. It appears that the commits in this repo only have a single newline after the first line of the commit message.

I've added a fix to auto-changelog that should sort this issue. I've also committed the fixed changelog as part of this PR, even though it will be fixed from now on every time you npm version.

People who contributed to this change:

• Pete Cook

[Rycochet]

I hadn't even noticed that was the issue - there's been a lot of commits with bad messages over the years here!