Add newlines to end of files so `cat` works better

Without the newlines at the end it looks like this when you `cat` the files, which is really annoying:

    [XXXXXXXXX@XXXXXXXXXXXX miniLock]$ cat CONTRIBUTING.md 
    #Contributing to miniLock
    
    ...
    
    ##Discussion & Blog
    * Coming soon.  
    
    ##Contributors
    * **Dmitry Chestnykh**: TweetNaCL library.  
    * **Nadim Kobeissi**: Lead developer. Created Cryptocat.  [XXXXXXXXX@XXXXXXXXXXXX miniLock]$