Update CHANGES.md

CHANGES.md

 # Changelog
 
-## 1.16 (unreleased)
--   Add unittests to automatically run when making/update a merge request.
+## 1.16 (2019-08-27)
+-   Add unittests to automatically run when making/updating a merge request.
     Also these tests can be run locally with `python setup.py test`
 
 -   Add additional tests based on
@@ -12,20 +12,21 @@
 -   Add lint to check style of code.
 
 -   Remove check for time window when uploading coincidence FAR since this
-    does not work for time windows for superevents and external events.
+    does not work for time windows for both superevents and external events.
 
 -   Remove commented code and unused legacy functions.
 
--   Change terms in GCN rates to be floats
+-   Change terms in GCN rates to be floats.
 
 -   Change format of time difference message to include three digits.
 
 -   Check that skymaps don't normalize to negative values.
 
--   Allow external sky map filename passed as argument so can use other
-    external sky maps.
+-   Allow external sky map filename to be passed as an argument, so can use
+    other external sky maps not just Fermi.
 
--   Fix search messages so that groups and pipelines no longer flip.
+-   Fix search messages to both be simpler and so that groups and pipelines
+    no longer flip.
 
 
 ## 1.15 (2019-07-02)