Fix shoulda-matchers require

Gemfile

@@ -255,7 +255,7 @@ end
 group :test do
   gem 'simplecov', require: false
-  gem 'shoulda-matchers', '~> 2.8.0'
+  gem 'shoulda-matchers', '~> 2.8.0', require: false
   gem 'email_spec'
   gem 'webmock', '~> 1.21.0'
   gem 'test_after_commit'

spec/spec_helper.rb

 ENV["RAILS_ENV"] ||= 'test'
 require File.expand_path("../../config/environment", __FILE__)
 require 'rspec/rails'
+require 'shoulda/matchers'
 require 'email_spec'
 require 'sidekiq/testing/inline'