Remove references to Python 3.5 in the documentation (Fixes #211)

docs/intro.rst

@@ -63,7 +63,7 @@ Client Features
 ---------------
 
 - Can connect to other Engine.IO complaint servers besides the one in this package.
-- Compatible with Python 3.5+.
+- Compatible with Python 3.6+.
 - Two versions of the client, one for standard Python and another for ``asyncio``.
 - Uses an event-based architecture implemented with decorators that hides the
   details of the protocol.
@@ -99,8 +99,7 @@ asynchronous server::
     if __name__ == '__main__':
         eventlet.wsgi.server(eventlet.listen(('', 5000)), app)
 
-Below is a similar application, coded for asyncio (Python 3.5+ only) and the
-Uvicorn web server::
+Below is a similar application, coded for asyncio and the Uvicorn web server::
 
     import engineio
     import uvicorn
@@ -131,7 +130,7 @@ Server Features
 
 - Can accept clients running other complaint Engine.IO clients besides the one in this
   package.
-- Compatible with Python 3.5+.
+- Compatible with Python 3.6+.
 - Two versions of the server, one for standard Python and another for ``asyncio``.
 - Supports large number of clients even on modest hardware due to being
   asynchronous.

docs/server.rst

@@ -358,8 +358,7 @@ aiohttp
 ~~~~~~~
 
 `aiohttp <http://aiohttp.readthedocs.io/>`_ provides a framework with support
-for HTTP and WebSocket, based on asyncio. Support for this framework is limited
-to Python 3.5 and newer.
+for HTTP and WebSocket, based on asyncio.
 
 Instances of class ``engineio.AsyncServer`` will automatically use aiohttp
 for asynchronous operations if the library is installed. To request its use
@@ -385,9 +384,8 @@ Tornado
 ~~~~~~~
 
 `Tornado <http://www.tornadoweb.org//>`_ is a web framework with support
-for HTTP and WebSocket. Support for this framework requires Python 3.5 and
-newer. Only Tornado version 5 and newer are supported, thanks to its tight
-integration with asyncio.
+for HTTP and WebSocket. Only Tornado version 5 and newer are supported, thanks
+to its tight integration with asyncio.
 
 Instances of class ``engineio.AsyncServer`` will automatically use tornado
 for asynchronous operations if the library is installed. To request its use
@@ -418,7 +416,7 @@ Sanic
 ~~~~~
 
 `Sanic <http://sanic.readthedocs.io/>`_ is a very efficient asynchronous web
-server for Python 3.5 and newer.
+server for Python.
 
 Instances of class ``engineio.AsyncServer`` will automatically use Sanic for
 asynchronous operations if the framework is installed. To request its use