Update license to Apache.

Author: bcho

setup.py

@@ -32,7 +32,7 @@
       download_url='https://github.com/neovim/python-client/archive/0.0.32.tar.gz',
       author='Thiago de Arruda',
       author_email='[email protected]',
-      license='MIT',
+      license='Apache',
       packages=['neovim', 'neovim.api', 'neovim.msgpack_rpc', 'neovim.ui',
                 'neovim.msgpack_rpc.event_loop', 'neovim.plugin'],
       install_requires=install_requires,