GitLab

The reason is that since the name of the license is not stated
explicitly and the license text differed very slightly I had to perform
a diff to ensure it actually is MIT licensed. Also GitHub does not
detect the license for this project currently (probably for the same
reason).

Changes:

* Remove the line 'Please consider promoting this project...' that is
  not part of the MIT license
* Use the same formatting as choosealicense.com
* Explicitly state 'MIT License'
* Update the copyright year