fix: switch to canonical broken-link-checker (#205)

Gemfile.lock

@@ -7,57 +7,61 @@ GEM
     asciidoctor (2.0.12)
     builder (3.2.4)
     charlock_holmes (0.7.7)
-    commonmarker (0.21.0)
+    commonmarker (0.21.2)
       ruby-enum (~> 0.5)
-    concurrent-ruby (1.1.7)
+    concurrent-ruby (1.1.8)
     creole (0.5.0)
     dotenv (2.7.6)
     escape_utils (1.2.1)
     expression_parser (0.9.0)
-    faraday (1.1.0)
+    faraday (1.3.0)
+      faraday-net_http (~> 1.0)
       multipart-post (>= 1.2, < 3)
       ruby2_keywords
-    github-linguist (7.12.1)
+    faraday-net_http (1.0.1)
+    github-linguist (7.13.0)
       charlock_holmes (~> 0.7.7)
       escape_utils (~> 1.2.0)
       mini_mime (~> 1.0)
       rugged (>= 0.25.1)
     github-markup (3.0.5)
     htmlentities (4.3.4)
-    i18n (1.8.5)
+    i18n (1.8.9)
       concurrent-ruby (~> 1.0)
     idn-ruby (0.1.0)
     json (1.8.6)
-    licensee (9.14.1)
+    licensee (9.15.1)
       dotenv (~> 2.0)
-      octokit (~> 4.17)
+      octokit (~> 4.20)
       reverse_markdown (~> 1.0)
       rugged (>= 0.24, < 2.0)
       thor (>= 0.19, < 2.0)
     mini_mime (1.0.2)
-    mini_portile2 (2.4.0)
+    mini_portile2 (2.5.0)
     multipart-post (2.1.1)
-    nokogiri (1.10.10)
-      mini_portile2 (~> 2.4.0)
-    octokit (4.19.0)
+    nokogiri (1.11.2)
+      mini_portile2 (~> 2.5.0)
+      racc (~> 1.4)
+    octokit (4.20.0)
       faraday (>= 0.9)
       sawyer (~> 0.8.0, >= 0.5.3)
     org-ruby (0.9.12)
       rubypants (~> 0.2)
     public_suffix (4.0.6)
+    racc (1.5.2)
     rdoc (3.12.1)
       json (~> 1.4)
     reverse_markdown (1.4.0)
       nokogiri
-    ruby-enum (0.8.0)
+    ruby-enum (0.9.0)
       i18n
-    ruby2_keywords (0.0.2)
+    ruby2_keywords (0.0.4)
     rubypants (0.7.1)
     rugged (1.1.0)
     sawyer (0.8.2)
       addressable (>= 2.3.5)
       faraday (> 0.8, < 2.0)
-    thor (1.0.1)
+    thor (1.1.0)
     twitter-text (3.1.0)
       idn-ruby
       unf (~> 0.1.0)