Trailing spaces in generated info

Not exactly an urgent issue, but the `PR-URL` and `Reviewed-By` lines each have a trailing space.

Looking through the code I can't see where they'd have been added.

#### E.g.
https://github.com/nodejs/node/pull/9645
```
PR-URL: https://github.com/nodejs/node/pull/9645 

Reviewed-By: Michael Dawson <michael_dawson@ca.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com> 
```