Polymer roll from 0.3.4 to 0.4.2.
Merge pull request #8 from toyoshim/polymer_roll_0.4.2

Polymer roll from 0.3.4 to 0.4.2.
Always initialize midi object even if Web MIDI is not available
Merge pull request #11 from toyoshim/midi_init

Always initialize midi object even if Web MIDI is not available
Fix a syntax error on wk-skelton.html
Merge pull request #12 from toyoshim/skelton

Fix a syntax error on wk-skelton.html