Bump redcarpet from 3.5.0 to 3.5.1 in /src

Bumps [redcarpet](https://github.com/vmg/redcarpet) from 3.5.0 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@v3.5.0...v3.5.1)

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

src/Gemfile

@@ -41,7 +41,7 @@ gem 'fancybox2-rails'
 gem 'annealer'
 
 gem 'icalendar', '~> 2.4'
-gem 'redcarpet', '~> 3.1'
+gem 'redcarpet', '~> 3.5'
 gem 'bcrypt-ruby', '~> 3.1'
 gem 'authlogic', '~> 4.2'
 gem 'cancancan'

src/Gemfile.lock

@@ -179,7 +179,7 @@ GEM
     rb-inotify (0.10.1)
       ffi (~> 1.0)
     rdoc (4.3.0)
-    redcarpet (3.5.0)
+    redcarpet (3.5.1)
     regexp_parser (1.7.1)
     request_store (1.5.0)
       rack (>= 1.4)
@@ -287,7 +287,7 @@ DEPENDENCIES
   rails (~> 5.2.3)
   rails-controller-testing
   rails_12factor
-  redcarpet (~> 3.1)
+  redcarpet (~> 3.5)
   responders (~> 2.0)
   rspec-rails (~> 3.1)
   ruby-progressbar