* Upgrade to Python3
* Add Travis tests
* General clean up
* Switch to pytest from nosetest
* rename `vertical_graph` to `vertical`
* rename `horizontal_graph` to `horizontal`
* add `character` and `characters` parameter fixes [2](https://github.com/markeganfuller/pytextgraph/issues/2).
* add dynamic sizing of horizontal graphs fixes [3](https://github.com/markeganfuller/pytextgraph/issues/3)
* change to tuples or `collections.OrderedDict` for labelled data fixes [1](https://github.com/markeganfuller/pytextgraph/issues/1)
* change versioning to semver fixes [4](https://github.com/markeganfuller/pytextgraph/issues/4)