Bumps version to 0.1.2.
Adds 0.1.2 updates to change log.
Release v0.1.2.

* Adds version information to ``__init__.py``.
* Adds Travis CI configuration information.
* Reformats ``README.rst``.
* Adds documentation about contributing.
* Fixes #2. Fixes segmenting text with whitespace.
* Fixes #3. Fixes ``_encode()``/``_decode`` default encoding error.