New concept of a MIDI keyboard.
Start of coding: can now play a simple sound.
Works quite well now. Once understanding the library, the programming was really simple
Added functionality and implemented an OOP approach (that looks nicer)
Updated README
Removed Extendability of recording to MIDI-files. Couldn't find a smooth way to do it (using pygame at least).
Updated README to course standard
Merge pull request #13 from introprogramming/exercise_midi

MIDI keyboard
As no one has mentioned anything they want differently for 15 days, I'm merging this now.