Also require all token plugin requirements

Token plugins are technically optional, but if you are installing
websockify via pip then all of these are available anyway. So let's make
things simple for users.

setup.py

@@ -29,7 +29,11 @@ setup(name=name,
 
       packages=['websockify'],
       include_package_data=True,
-      install_requires=['numpy'],
+      install_requires=[
+        'numpy', 'requests',
+        'jwcrypto',
+        'redis', 'simplejson',
+        ],
       zip_safe=False,
       entry_points={
         'console_scripts': [