Google Cloud API Client initialization inconsistent

[frankyn]

Story

Rubyist knows to use Google Data Store API. Rubyist wants to learn Google Vision API and the samples use different Google Cloud API Client initialization. Confusion begins.

Issue
Initialization is inconsistent between these two samples. The issue may exist in other samples within the Ruby space.

DataStore uses
require "gcloud"
gcloud = Gcloud.new
datastore = gcloud.datastore

Vision uses
require "google/cloud"
gcloud = Google::Cloud.new
vision = gcloud.vision

Issue exists in the following locations:
appengine/datastore/app.rb
appengine/pubsub/app.rb
appengine/pubsub/spec/pubsub_spec.rb
bigquery/shakespeare.rb
datastore/sample.rb
logging/spec/sample_spec.rb
logging/sample.rb
pubsub/sample.rb

Possible Solution
Use the same initialization in all Ruby samples.

[beccasaurus]

Duplicate of #55

Fix pending in #65