Bump version and changelog

CHANGES.rst

-Changes in synapse v0.17.0-rc2 (2016-08-02)
+Changes in synapse v0.17.0-rc3 (2016-08-02)
 ===========================================
 
 Changes:
@@ -15,6 +15,12 @@ Bug fixes:
 * Fix adding emails on registration (PR #968)
 
 
+Changes in synapse v0.17.0-rc2 (2016-08-02)
+===========================================
+
+(This release did not include the changes advertised and was identical to RC1)
+
+
 Changes in synapse v0.17.0-rc1 (2016-07-28)
 ===========================================
 

synapse/__init__.py

@@ -16,4 +16,4 @@
 """ This is a reference implementation of a Matrix home server.
 """
 
-__version__ = "0.17.0-rc2"
+__version__ = "0.17.0-rc3"