Tox, Travis, and Appveyor improvements

[mark-adams]

• Added appveyor support (Thanks @mindw)
• Added tox configuration improvements (Thanks @mindw)
• Added travis configuration improvements (Thanks @mindw)
• Excluded __main__.py from coverage

cc: @jpadilla

[jpadilla]

Let's change this for what I proposed earlier. get_version() works well.

[mark-adams]

Can you remind me what you proposed?

[jpadilla]

Just do the same.

def get_version(package):
    """
    Return package version as listed in `__version__` in `init.py`.
    """
    init_py = open(os.path.join(package, '__init__.py')).read()
    return re.search("__version__ = ['\"]([^'\"]+)['\"]", init_py).group(1)

version = get_version('jwt')

[jpadilla]

lol I think that's failing because of the é in my first name

[jpadilla]

I wonder if this might do.

codecs.open(os.path.join(package, '__init__.py'), 'r', 'utf-8').read()

[coveralls]

Coverage decreased (-0.42%) to 99.58% when pulling a801e3e on mark-adams:tox-and-appveyor into fdd477a on jpadilla:master.

[mark-adams]

Coverage won't really go down. Once #159 removes the old Python 3.2-only compatibility code, it'll be back to normal.

What do you think @jpadilla?

[jpadilla]

@mark-adams LGTM, all yours, thanks! I'll get the Appveyor account setup.

[jpadilla]

This will need rebasing after merging #159

[jpadilla]

Repo already set at AppVeyor: https://ci.appveyor.com/project/jpadilla/pyjwt

[coveralls]

Coverage remained the same at 100.0% when pulling 235aa82 on mark-adams:tox-and-appveyor into b4ede91 on jpadilla:master.