Adding doc.go to sphero package
Correct indentation for doc.go in sphero package
Adding doc.go to gpio package
Merge branch 'dev' of github.com:hybridgroup/gobot into ardrone-godoc

* 'dev' of github.com:hybridgroup/gobot:
  Adding doc.go to gpio package
  Correct indentation for doc.go in sphero package
  Adding doc.go to sphero package