Bump rspec-rails from 3.9.1 to 4.0.0

Bumps [rspec-rails](https://github.com/rspec/rspec-rails) from 3.9.1 to 4.0.0.
- [Release notes](https://github.com/rspec/rspec-rails/releases)
- [Changelog](https://github.com/rspec/rspec-rails/blob/master/Changelog.md)
- [Commits](rspec/rspec-rails@v3.9.1...v4.0.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Gemfile.lock

@@ -308,20 +308,20 @@ GEM
       rspec-expectations (>= 2.99.0.beta1)
     rspec-core (3.9.1)
       rspec-support (~> 3.9.1)
-    rspec-expectations (3.9.0)
+    rspec-expectations (3.9.1)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.9.0)
     rspec-mocks (3.9.1)
       diff-lcs (>= 1.2.0, < 2.0)
       rspec-support (~> 3.9.0)
-    rspec-rails (3.9.1)
-      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)
+      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 (3.9.2)
     rubocop (0.80.1)
       jaro_winkler (~> 1.5.1)