Update version and changelog

CHANGES.rst

+Changes in synapse v0.19.1 (2017-02-09)
+=======================================
+
+* Fix bug where state was incorrectly reset in a room when synapse received an
+  event over federation that did not pass auth checks (PR #1892)
+
+
 Changes in synapse v0.19.0 (2017-02-04)
 =======================================
 

synapse/__init__.py

@@ -16,4 +16,4 @@
 """ This is a reference implementation of a Matrix home server.
 """
 
-__version__ = "0.19.0"
+__version__ = "0.19.1"