Add console.error statement (#672)

Author: Ace Nassri

functions/log/index.js

@@ -18,6 +18,7 @@
 // [START functions_log_helloworld]
 exports.helloWorld = (event, callback) => {
   console.log('I am a log entry!');
+  console.error('I am an error!');
   callback();
 };
 // [END functions_log_helloworld]