Bump govuk_template to 0.20.0

# 0.20.0

- Fix EJS template - PR #270 -
alphagov/govuk_template#270
- Add `theme-color` support to make the page surround in Chrome’s tab
view on Android match the black GOV.UK header - PR #278 -
alphagov/govuk_template#278
- Add `text-decoration-skip: ink` to all links on GOV.UK - PR #281 -
alphagov/govuk_template#281
- Improve contrast of links when focused - PR #272 -
alphagov/govuk_template#272
- Make header text colour black when focused - PR #274 -
alphagov/govuk_template#274

# 0.19.2

- Increase skiplink colour contrast - PR #263 -
alphagov/govuk_template#263
- Fix Scala compile issues for Play template - PR #261 -
alphagov/govuk_template#261

# 0.19.1

- Have focus outline appear outside of element rather than covering it
in Safari and Chrome - PR #259 -
alphagov/govuk_template#259

Gemfile

@@ -46,6 +46,6 @@ gem 'govuk_frontend_toolkit', '~> 6.0.1'
 if ENV['GOVUK_TEMPLATE_DEV']
   gem 'govuk_template', :path => "../govuk_template"
 else
-  gem 'govuk_template', '0.19.0'
+  gem 'govuk_template', '0.20.0'
 end
 gem 'gds-api-adapters', '41.2.0'

Gemfile.lock

@@ -88,7 +88,7 @@ GEM
     govuk_frontend_toolkit (6.0.1)
       rails (>= 3.1.0)
       sass (>= 3.2.0)
-    govuk_template (0.19.0)
+    govuk_template (0.20.0)
       rails (>= 3.1)
     http-cookie (1.0.3)
       domain_name (~> 0.5)
@@ -258,7 +258,7 @@ DEPENDENCIES
   govuk-content-schema-test-helpers (~> 1.4)
   govuk-lint (~> 0.6.0)
   govuk_frontend_toolkit (~> 6.0.1)
-  govuk_template (= 0.19.0)
+  govuk_template (= 0.20.0)
   image_optim (= 0.17.1)
   jasmine-rails (~> 0.10.6)
   logstasher (= 0.4.8)