Bump html-proofer from 3.15.1 to 3.15.2

Bumps [html-proofer](https://github.com/gjtorikian/html-proofer) from 3.15.1 to 3.15.2.
- [Release notes](https://github.com/gjtorikian/html-proofer/releases)
- [Commits](gjtorikian/html-proofer@v3.15.1...v3.15.2)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]

Gemfile.lock

@@ -28,7 +28,7 @@ GEM
     execjs (2.7.0)
     faraday (1.0.0)
       multipart-post (>= 1.2, < 3)
-    ffi (1.12.1)
+    ffi (1.12.2)
     forwardable-extended (2.6.0)
     gemoji (3.0.1)
     github-pages (204)
@@ -83,7 +83,7 @@ GEM
     html-pipeline (2.12.3)
       activesupport (>= 2)
       nokogiri (>= 1.4)
-    html-proofer (3.15.1)
+    html-proofer (3.15.2)
       addressable (~> 2.3)
       mercenary (~> 0.3)
       nokogumbo (~> 2.0)
@@ -212,7 +212,7 @@ GEM
       jekyll-seo-tag (~> 2.1)
     minitest (5.14.0)
     multipart-post (2.1.1)
-    nokogiri (1.10.8)
+    nokogiri (1.10.9)
       mini_portile2 (~> 2.4.0)
     nokogumbo (2.0.2)
       nokogiri (~> 1.8, >= 1.8.4)
@@ -249,7 +249,7 @@ GEM
     tzinfo (1.2.6)
       thread_safe (~> 0.1)
     unicode-display_width (1.6.1)
-    yell (2.2.1)
+    yell (2.2.2)
     zeitwerk (2.2.2)
 
 PLATFORMS