fixed notebook to work on current public colab+tf (#48)
fixed notebook to work on current public colab+tf (#48)

fixed the notebook so that the demo works in colab now (I had to download magenta, and deal with some legacy int <-> binary issue). Attached is the version that I tested on colab to make sure it worked.
magenta/magenta-demos,magenta/magenta-demos,magenta/magenta-demos,magenta/magenta-demos,magenta/magenta-demos