tag implementation (add, remove, list, add device_token to tag, remove device_token to tag
added tag methods
Merge pull request #20 from WillCall/tags_implementation

tag implementation (add, remove, list, add device_token to tag, remove d...
added tag usage
changed some method names
added sample usage for sending push to tags, as well as including tags and aliases in device registration
added segment push methods, tests, and usage
added segment push methods, tests, and usage
changed method names
Merge pull request #21 from WillCall/tags_implementation

tags and segment push implementation
readme touchups
removing whitespace
readme touchup
version bump to 2.2.1