Feature/legato in browser

@dansomething  Finally got the builds passing again! I was having issues because installing legato to run it in the browser was failing on Travis when it tried to install the midi dependencies. I ended up using git to install legato during CI builds. Let me know if I messed up any of your changes in my merging.
That's right. Installing the midi dependencies causes npm to try to compile the underlaying rtMidi libraries. These fail to compile on Travis because of missing system dependencies. Here's where it failed: https://travis-ci.org/OSCModulator/oscmodulator/builds/38968639#L239