[scikit-learn] Code review

[olologin]

Hi guys, I know scikit-learn may not be your main project, and you all 
are very busy at work so you don't have free time to review all pull 
requests, I understand it.

Is there something project leaders can do to speed-up review process? 
Because I have bunch of pull requests which I made 5-7 months ago, and 
they are relatively useful :), but they wasn't reviewed. Some of them 
are quite simple for review (~10 lines in python), and still have only 1 
vote. Maybe it's possible to increase size of team which have permission 
to review? Or all I can do is just wait? :)

I'm writing this letter because yesterday one guy complained about this 
in one of my PR's (I forgot about that PR by the time) 
https://github.com/scikit-learn/scikit-learn/pull/6116#issuecomment-227044224.