added badges and install instructions
use sphinx for documentation
added structure to docs
added missing docstrings
reformatted changelog for consumption in docs
reuse text from docs in README file
added docs build folder to ignore list
renamed requirements file
added make target for building docs
build docs for python 3.x as part of tox run
updated travis config after requirements file rename
Merge pull request #5 from ricardokirkner/readme-please

added initial documentation