Merge pull request #114 from cv65/patch-1

Update README.rst

Author: brentru

README.rst

@@ -35,6 +35,13 @@ If you have `PIP <https://pip.pypa.io/en/stable/installing/>`_ installed (typica
 
 This will automatically install the Adafruit IO Python client code for your Python scripts to use. You might want to examine the examples folder in this GitHub repository to see examples of usage.
 
+If the above command fails, you may first need to install prerequisites:
+
+.. code-block:: shell
+
+   pip3 install setuptools
+   pip3 install wheel
+
 
 Manual Installation
 ~~~~~~~~~~~~~~~~~~~