Add license file and tests to source distribution (sdist)

[koobs]

The LICENSE.txt file in the repository is missing from the PyPi source distribution (sdist). You likely want a MANIFEST.in to do this. That will allow me to package the relevant license in the FreeBSD Ports I've created for slackclient.

While you're there, you may want to add Copyright details to the LICENSE.txt head

[rawdigits]

Thanks for packaging this in ports, and apologies on the delayed reply! I'm doing some small updates and will push to pypi with a proper license.txt.

[koobs]

My pleasure Ryan, thanks for the ack

[jammons]

Ok, only a year and a bit late. I just published v1.0.1 to pypi with the LICENSE file included.

https://pypi.python.org/pypi?:action=display&name=slackclient&version=1.0.1

Sorry for the delay! Thanks again for getting this into Ports