E-lti

--------------------

Include oauth_body_hash parameter in outcome request

------------------

* added some launch params specific to the Canvas editor
* added contributor section to README

------------------

setup.py needs to use find_packages to find contrib stuff

------------------

Project officially forked and renamed from [ims_lti_py](https://github.com/tophatmonocle/ims_lti_py) at v0.6. README update and HISTORY added.

------------------

Updating project to utilize the oauthlib python library.

* convert from python-oauth2 to oauthlib & requests-oauthlib
* refactored out use of mixin classes
* LaunchParams as first class object
* Major rewrite and rename of test suite
* Use of semver version identifier
* Use of pytest and tox for test running