mzrestazure on PyPi missing readme.rst

[phyber]

As the subject says, the release of msrestazure on PyPi is missing the readme.rst file which is used to generate the long_description in setup.py. This means that installations of msrestazure from pip fail.
This also affects other software that ends up pulling in msrestazure long the way.

[stankovski]

@xingwu1 please take a look at this

[lmazuel]

Got it, will do a PR soon

[lmazuel]

Associated release of msrest/msrestazure
#761