added rspec step in tests stage, adjusted should clause

Jenkinsfile

@@ -26,6 +26,7 @@ pipeline {
     stage('Run tests') {
       steps {
         sh 'cucumber features --format html --out coverage/cucumber.html'
+        sh 'rspec spec'
       }
     }
     stage('Report results') {

spec/create_spec.rb

@@ -0,0 +1,21 @@
+require_relative '../.env'
+ENV["DB_NAME"] = "test_#{ENV["DB_NAME"]}"
+require_relative '../app'
+require 'rubygems'
+require 'roda'
+require 'sequel'
+require 'rspec'
+require 'rack/test'
+
+def app
+  App
+end
+
+describe "Submit API request to create new link" do
+  include Rack::Test::Methods
+  it "should return link data in json format" do
+    post '/create'
+    last_response.should be_ok
+  end
+end
+