Minor cleanups in Led class
v0.8.12
Led.prototype.strobe doesn't need to change the mode to OUTPUT
v0.8.13
Merge branch 'master' of https://github.com/rwaldron/johnny-five

# By Rick Waldron
# Via Rick Waldron
* 'master' of https://github.com/rwaldron/johnny-five:
  v0.8.13
  Led.prototype.strobe doesn't need to change the mode to OUTPUT
  v0.8.12
  Minor cleanups in Led class