Only support Python 3.6

Yeah, I don't feel like setting up multiple Pythons for Pocketsphinx and
making a real test suite to ensure everything is working for 3.5.  I'm
planning on using provisional APIs (specifically the `typing` module) so
I won't make any claim to support any version of Python other than the
one I'm developing with.

README.rst

 Dependencies
 ~~~~~~~~~~~~
 
-1. Python 3 (tested with 3.5, may work with older versions)
+1. Python 3.6
 2. pocketsphinx 5prealpha
 3. gstreamer-1.0 (and what ever plugin has pocketsphinx support)
 4. gstreamer-1.0 base plugins (required for ALSA)

setup.py

             "(GPLv3+)",
         "Operating System :: POSIX :: Linux",
         "Programming Language :: Python :: 3 :: Only",
-        "Programming Language :: Python :: 3.5",
+        "Programming Language :: Python :: 3.6",
         "Topic :: Home Automation"
     ],
     install_requires=["requests", "setuptools"],