Bundle update rspec-rails

We need to this to support testing Sidekiq jobs inline, see
rails/rails#37270 and
rspec/rspec-rails#2242 for more information.

Gemfile

@@ -46,7 +46,7 @@ group :development, :test do
   gem "rack", ">= 2.0.6"
   gem 'rails-controller-testing'
   gem 'rspec-its'
-  gem 'rspec-rails'
+  gem 'rspec-rails', '4.0.0.beta4'
   gem 'shoulda-matchers'
   gem 'simplecov', require: false
   gem 'spring'

Gemfile.lock

@@ -324,17 +324,17 @@ GEM
     rspec-its (1.3.0)
       rspec-core (>= 3.0.0)
       rspec-expectations (>= 3.0.0)
-    rspec-mocks (3.9.0)
+    rspec-mocks (3.9.1)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.9.0)
-    rspec-rails (3.9.0)
-      actionpack (>= 3.0)
-      activesupport (>= 3.0)
-      railties (>= 3.0)
-      rspec-core (~> 3.9.0)
-      rspec-expectations (~> 3.9.0)
-      rspec-mocks (~> 3.9.0)
-      rspec-support (~> 3.9.0)
+    rspec-rails (4.0.0.beta4)
+      actionpack (>= 4.2)
+      activesupport (>= 4.2)
+      railties (>= 4.2)
+      rspec-core (~> 3.9)
+      rspec-expectations (~> 3.9)
+      rspec-mocks (~> 3.9)
+      rspec-support (~> 3.9)
     rspec-support (3.9.0)
     rubocop (0.77.0)
       jaro_winkler (~> 1.5.1)
@@ -465,7 +465,7 @@ DEPENDENCIES
   rails-controller-testing
   rails-erd
   rspec-its
-  rspec-rails
+  rspec-rails (= 4.0.0.beta4)
   rubocop-govuk (~> 2)
   ruby-progressbar
   scenic