Bump html-proofer from 3.12.0 to 3.12.2

Bumps [html-proofer](https://github.com/gjtorikian/html-proofer) from 3.12.0 to 3.12.2.
- [Release notes](https://github.com/gjtorikian/html-proofer/releases)
- [Commits](gjtorikian/html-proofer@v3.12.0...v3.12.2)

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

Author: dependabot-preview[bot]

Gemfile.lock

@@ -13,13 +13,12 @@ GEM
     eventmachine (1.2.7)
     ffi (1.11.1)
     forwardable-extended (2.6.0)
-    html-proofer (3.12.0)
+    html-proofer (3.12.2)
       addressable (~> 2.3)
       mercenary (~> 0.3)
       nokogiri (~> 1.10)
       parallel (~> 1.3)
       rainbow (~> 3.0)
-      timerizer (~> 0.3)
       typhoeus (~> 1.3)
       yell (~> 2.0)
     http_parser.rb (0.6.0)
@@ -72,7 +71,6 @@ GEM
     sass-listen (4.0.0)
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
-    timerizer (0.3.2)
     typhoeus (1.3.1)
       ethon (>= 0.9.0)
     yell (2.2.0)