Update GOV.UK Frontend Toolkit to v5.1.1

v5.1.1 of GOV.UK Frontend Toolkit includes a fix[1] for a bug in stick-at-top-when-scrolling where the page ‘jumps’ when the in page navigation ‘sticks’[2], introduced by the Scroll Anchoring functionality present in Chrome 56 and above[3].

[1]: alphagov/govuk_frontend_toolkit#376
[2]: http://webarchive.nationalarchives.gov.uk/20161126131022/https://www.gov.uk/service-manual/agile-delivery/agile-government-services-introduction
[3]: https://bugs.chromium.org/p/chromium/issues/detail?id=687118

Gemfile

@@ -3,7 +3,7 @@ source 'https://rubygems.org'
 ruby File.read(".ruby-version").strip
 
 gem 'airbrake', '4.0'
-gem 'govuk_frontend_toolkit', '5.0.0'
+gem 'govuk_frontend_toolkit', '~> 5.1.0'
 gem 'logstasher', '0.6.1'
 gem 'plek', '1.11'
 gem 'rails', '4.2.7.1'

Gemfile.lock

@@ -44,7 +44,7 @@ GEM
     anemone (0.7.2)
       nokogiri (>= 1.3.0)
       robotex (>= 1.0.0)
-    arel (6.0.3)
+    arel (6.0.4)
     ast (2.2.0)
     astrolabe (1.3.1)
       parser (~> 2.2)
@@ -54,7 +54,7 @@ GEM
       rack (>= 0.9.0)
     binding_of_caller (0.7.2)
       debug_inspector (>= 0.0.1)
-    builder (3.2.2)
+    builder (3.2.3)
     byebug (8.2.1)
     capybara (2.6.2)
       addressable
@@ -66,7 +66,7 @@ GEM
     casperjs (1.0.0)
     cliver (0.3.2)
     coderay (1.1.0)
-    concurrent-ruby (1.0.2)
+    concurrent-ruby (1.0.4)
     crack (0.4.3)
       safe_yaml (~> 1.0.0)
     debug_inspector (0.0.2)
@@ -88,20 +88,20 @@ GEM
     govuk-lint (0.6.1)
       rubocop (~> 0.35.0)
       scss_lint (~> 0.44.0)
-    govuk_frontend_toolkit (5.0.0)
+    govuk_frontend_toolkit (5.1.1)
       rails (>= 3.1.0)
       sass (>= 3.2.0)
     http-cookie (1.0.3)
       domain_name (~> 0.5)
-    i18n (0.7.0)
+    i18n (0.8.0)
     image_size (1.4.1)
     jasmine-core (2.5.0)
     jasmine-rails (0.13.0)
       jasmine-core (>= 1.3, < 3.0)
       phantomjs (>= 1.9)
       railties (>= 3.2.0)
       sprockets-rails
-    json (1.8.3)
+    json (1.8.6)
     json-schema (2.5.2)
       addressable (~> 2.3.8)
     kgio (2.10.0)
@@ -122,7 +122,7 @@ GEM
       mime-types-data (~> 3.2015)
     mime-types-data (3.2016.0521)
     mini_portile2 (2.0.0)
-    minitest (5.9.1)
+    minitest (5.10.1)
     multi_json (1.11.2)
     netrc (0.11.0)
     nokogiri (1.6.7)
@@ -164,9 +164,9 @@ GEM
       sprockets-rails
     rails-deprecated_sanitizer (1.0.3)
       activesupport (>= 4.2.0.alpha)
-    rails-dom-testing (1.0.7)
+    rails-dom-testing (1.0.8)
       activesupport (>= 4.2.0.beta, < 5.0)
-      nokogiri (~> 1.6.0)
+      nokogiri (~> 1.6)
       rails-deprecated_sanitizer (>= 1.0.1)
     rails-html-sanitizer (1.0.3)
       loofah (~> 2.0)
@@ -199,7 +199,7 @@ GEM
       tins (<= 1.6.0)
     ruby-progressbar (1.7.5)
     safe_yaml (1.0.4)
-    sass (3.4.22)
+    sass (3.4.23)
     sass-rails (5.0.6)
       railties (>= 4.0.0, < 6)
       sass (~> 3.1)
@@ -218,14 +218,14 @@ GEM
       rack
       rest-client
     slop (3.6.0)
-    sprockets (3.7.0)
+    sprockets (3.7.1)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
-    sprockets-rails (3.1.1)
+    sprockets-rails (3.2.0)
       actionpack (>= 4.0)
       activesupport (>= 4.0)
       sprockets (>= 3.0.0)
-    thor (0.19.1)
+    thor (0.19.4)
     thread_safe (0.3.5)
     tilt (2.0.5)
     tins (1.6.0)
@@ -276,7 +276,7 @@ DEPENDENCIES
   gds-api-adapters (~> 37.5)
   govuk-content-schema-test-helpers (= 1.1.0)
   govuk-lint
-  govuk_frontend_toolkit (= 5.0.0)
+  govuk_frontend_toolkit (~> 5.1.0)
   jasmine-rails
   logstasher (= 0.6.1)
   phantomjs (~> 1.9.7)