CHANGELOG.md in google-cloud-datastore-1.7.2 vs CHANGELOG.md in google-cloud-datastore-1.7.3

@@ -1,6 +1,12 @@
 # Release History
 
+### 1.7.3 / 2020-01-23
+
+#### Documentation
+
+* Update copyright year
+
 ### 1.7.2 / 2019-12-12
 
 #### Bug Fixes
 
 * Update some positional params to keyword args in the lower-level API to match the backend service.