Update for httpsig 1.1

Removed version requirement for httpsig from requirements.

Updated to 1.0b2

* Added versioneer.
* Updated requirements to use latest httpsig.
* Added "setup.py test" and tox support.
* Fixed a unit test.

documented workaround for installation issue

updated version to 0.1.4

bumped version to 0.1.3 after uploading to PyPI

bumped to veersion 0.1.2