Implement mediawiki oauth using mwoauth

https://github.com/wikimedia/MediaWiki-OAuth
https://pypi.python.org/pypi/mwoauth

mwoauth is py2.7+ while pywikibot is py2.6+ , but this can be a feature not supported on py2.6.

The list of dependencies is reasonable, except that it is restricted to not using PyJWT unplanned future version v2, which is a bit odd but doesnt hurt at present (maybe @Halfak can explain...?)

https://github.com/wikimedia/MediaWiki-OAuth/blob/master/setup.py

install_requires=[
    'PyJWT>=1.0.1,<2.0.0',
    'oauthlib',
    'requests',
    'requests-oauthlib',
    'six'
],