Bump redcarpet from 3.4.0 to 3.5.1

Bumps [redcarpet](https://github.com/vmg/redcarpet) from 3.4.0 to 3.5.1.
- [Release notes](https://github.com/vmg/redcarpet/releases)
- [Changelog](https://github.com/vmg/redcarpet/blob/master/CHANGELOG.md)
- [Commits](vmg/redcarpet@v3.4.0...v3.5.1)

---
updated-dependencies:
- dependency-name: redcarpet
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Gemfile

@@ -7,6 +7,6 @@ gem 'middleman-syntax', '~> 3.0'
 gem 'middleman-autoprefixer', '~> 2.7'
 gem 'middleman-sprockets', '~> 4.1'
 gem 'rouge', '~> 2.0.5'
-gem 'redcarpet', '~> 3.4.0'
+gem 'redcarpet', '~> 3.5.1'
 gem 'nokogiri', '~> 1.10.4'
 gem 'sass'

Gemfile.lock

@@ -93,7 +93,7 @@ GEM
     rb-fsevent (0.10.3)
     rb-inotify (0.10.0)
       ffi (~> 1.0)
-    redcarpet (3.4.0)
+    redcarpet (3.5.1)
     rouge (2.0.7)
     sass (3.7.4)
       sass-listen (~> 4.0.0)
@@ -125,7 +125,7 @@ DEPENDENCIES
   middleman-sprockets (~> 4.1)
   middleman-syntax (~> 3.0)
   nokogiri (~> 1.10.4)
-  redcarpet (~> 3.4.0)
+  redcarpet (~> 3.5.1)
   rouge (~> 2.0.5)
   sass