For single line Git commit messages, the close quote should be on the same line as the open quote

_Originally opened at !7299 by @jzinn._

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## What does this MR do?

Chomps merge commit messages so that there is not a dangling close quote.

A better solution would be not to use quotes at all, but to set off the message in a `<div>` with a background color.

## Screenshots (if relevant)

![Screen_Shot_2016-11-04_at_8.06.54_PM](/uploads/6e749c5227d88a9bfea64e70cccaf14a/Screen_Shot_2016-11-04_at_8.06.54_PM.png)

See merge request !7975