New samples for Cloud Functions docs (#132)

* Add HTTP Cloud Function.

* Add more GCF http samples.

* Change string

* Added promise sample.

* Add background functions tests.

* Added more GCF tests.

* Fix readme and make test work in Node 0.12

* Changed helloworld to camel case (#133)

* Changed helloworld to camel case (#134)

* Add BigQuery processing to SendGrid sample (still needs more tests).

* Add basic auth check.

* Add fix for property names

* Make fixNames method recursive.

* Changed helloworld to camel case (#136)

* Add small helloGET sample.

* Tweak some hello world samples.

* Finish sendgrid unit tests.

* Add missing readme link.

* Update comment.

* Make sure a response gets sent.

* Made requested fixes.

* Final fixes.

* Couple fixes to fix test flakiness.

monitoring/snippets/create_custom_metric.js

@@ -121,7 +121,10 @@ CustomMetrics.prototype.writeTimeSeriesForCustomMetric =
       resource: {
         timeSeries: [{
           metric: {
-            type: this.metricType
+            type: this.metricType,
+            labels: {
+              environment: 'production'
+            }
           },
           resource: {
             type: 'gce_instance',