Add note about Python 2/3

Author: dariusf

README.md

@@ -1,6 +1,8 @@
-# [:] Example Python Project
+# [:] Example Python 2 Project
 
-An example python project to demonstrate [srcclr](https://www.srcclr.com) scans.
+An example Python project to demonstrate [srcclr](https://www.srcclr.com) scans.
+
+Check out the [python3](https://github.com/srcclr/example-python/tree/python3) branch for a project that builds with Python 3.
 
 ## Try me!