added rspec step in tests stage, adjusted should clause

spec/create_spec.rb

@@ -13,7 +13,7 @@ end
 
 describe "Submit API request to create new link" do
   include Rack::Test::Methods
-  it "should return a link to the url provided" do
+  it "should return link data in json format" do
     post '/create'
     last_response.should be_ok
   end