Fix formatting of diff lines

[tgs]

This patch leaves \n off the end of the diff's header lines, since the newline is added again by other code. It fixes a small formatting glitch in failing tests:

Before:

After:

[nicoddemus]

Awesome, thanks a lot @tgs!

I will make a new release with this tomorrow. 👍

[tgs]

Great, thank you! 😁

…

On Mon, Nov 19, 2018 at 6:22 PM Bruno Oliveira ***@***.***> wrote: Awesome, thanks a lot @tgs <https://github.com/tgs>! I will make a new release with this tomorrow. 👍 — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#15 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAOAfpBVSKc6wsLvWLrrHMP54NV_eCnYks5uwz0ygaJpZM4Yp1Yk> .

[nicoddemus]

Published, thanks!