Amend Readme about virtual environment; add link to setup info

README.md

@@ -36,8 +36,9 @@ We provide several meta-packages to help you install several packages at a time.
 
     This sample (and the SDK) is compatible with Python 2.7, 3.3, 3.4, 3.5 and 3.6.
 
-2.  We recommend that you use a [virtual environment](https://docs.python.org/3/tutorial/venv.html)
-    to run this example, but it's not required.
+2.  General recommendation for Python development is to use a Virtual Environment. 
+    For more information, see https://docs.python.org/3/tutorial/venv.html
+
     Install and initialize the virtual environment with the "venv" module on Python 3 (you must install [virtualenv](https://pypi.python.org/pypi/virtualenv) for Python 2.7):
 
     ```