Merge branch 'patch-24' into 'master'

Update rouge to 3.15.0

See merge request gitlab-org/gitlab!23364

Gemfile

@@ -150,7 +150,7 @@ gem 'wikicloth', '0.8.1'
 gem 'asciidoctor', '~> 2.0.10'
 gem 'asciidoctor-include-ext', '~> 0.3.1', require: false
 gem 'asciidoctor-plantuml', '0.0.10'
-gem 'rouge', '~> 3.11.0'
+gem 'rouge', '~> 3.15.0'
 gem 'truncato', '~> 0.7.11'
 gem 'bootstrap_form', '~> 4.2.0'
 gem 'nokogiri', '~> 1.10.5'

Gemfile.lock

@@ -873,7 +873,7 @@ GEM
     retriable (3.1.2)
     rinku (2.0.0)
     rotp (2.1.2)
-    rouge (3.11.0)
+    rouge (3.15.0)
     rqrcode (0.7.0)
       chunky_png
     rqrcode-rails3 (0.1.7)