add index rspec test to suggestions

spec/acceptance/suggestions_spec.rb

@@ -6,6 +6,13 @@ resource 'Suggestions' do
 
   let(:suggestions) { Suggestion.all }
 
+  get '/v1/suggestions' do
+
+    example_request 'Getting all suggestions' do
+      expect(status).to eq(200)
+    end
+  end
+
   get '/v1/suggestions/:id' do
 
     let(:id) { suggestions.first.id }