samples: Auto-update dependencies. (googleapis#636)

* Auto-update dependencies.

* Roll back speech & Vision due to weird GAX issues.
Fix for GA Datastore, Storage, and more.

* Fix pom.xml

Downgrade to prior version.

samples/snippets/src/main/java/com/example/spanner/QuickstartSample.java

@@ -57,7 +57,7 @@ public static void main(String... args) throws Exception {
       }
     } finally {
       // Closes the client which will free up the resources used
-      spanner.closeAsync().get();
+      spanner.closeAsync();
     }
   }
 }