Make purpose clearer

Closes gh-51

Author: takluyver

_sections/20-statement.md

@@ -4,7 +4,7 @@ bg: '#4da45e'
 color: white
 ---
 
-# Python 3 Statement
+# Moving to require Python 3
 
 All of the major projects making up the Scientific Python stack now support
 both Python 3.x and Python 2.7, and many projects have been supporting these

_sections/30-projects.md

@@ -8,6 +8,8 @@ style: center
 
 # Participating Projects
 
+These projects pledge to drop Python 2 support in or before 2020.
+
 - [![](assets/ipython.png)IPython](https://ipython.org)
 - [![](assets/jupyter.png)Jupyter notebook](https://jupyter.org)
 - [![](assets/pandas.png)pandas](http://pandas.pydata.org/)