Set Stepper pins to MODES.STEPPER. Fixes gh-467
v0.8.20
Added Gitter badge
Update readme
Move Fn tests to test/fn.js. Adds _BV/bitValue
Added Gitter badge
Moved badge to template
Merge pull request #471 from gitter-badger/gitter-badge

Add a Gitter chat badge to README.md
Rebuild with badge
Merge remote-tracking branch 'upstream/master'