fixing FCM url

fixing docs

fixing flake8 issues

adding travis configuration

setting up fcm publish script.

first version of fcm refactor

refactoring to get rid of plaintext and support notifications

Add GCM priority support and bump version to 0.1.5.

Merged in goeran/gcm-client/python-3.3 (pull request #2)

Added a comment in the code about decoding issue

Parsing the text representation of the response instead of content (bytes).

Added support for python 3.3 by using six.

Created new branch python-3.3

Release 0.1.4

Accept 0, it's a legitimate time_to_live value.