Update CI script and readme

- Rename README to README.md so that it displays as Markdown on GitHub.
- Reformat readme to Markdown.
- Add Python 3.4 to CI build matrix so that we can see what would need to
  change to allow support for Python 3.
- Set build matrix to allow failures for Python 2.7 and 3.4 as they do
  not need to be supported at the moment.
- Set CI file to fast finish so we don't have to wait for builds of
  versions that are allowed to fail.