CHANGELOG.md in google-cloud-bigtable-0.3.0 vs CHANGELOG.md in google-cloud-bigtable-0.3.1

@@ -1,16 +1,23 @@
 # Release History
 
+### 0.3.1 / 2019-04-29
+
+* Add AUTHENTICATION.md guide.
+* Update generated documentation.
+* Update generated code examples.
+* Extract gRPC header values from request.
+
 ### 0.3.0 / 2019-02-01
 
 * Move library to Beta.
 * Make use of Credentials#project_id
   * Use Credentials#project_id
     If a project_id is not provided, use the value on the Credentials object.
     This value was added in googleauth 0.7.0.
   * Loosen googleauth dependency
     Allow for new releases up to 0.10.
-    The googleauth devs have committed to maintanining the current API
+    The googleauth devs have committed to maintaining the current API
     and will not make backwards compatible changes before 0.10.
 
 ### 0.2.0 / 2018-11-15
 
 * Update network configuration.