discourse.plugins: Update and add metadata

(cherry picked from commit d3bc5d5b7a9e0d5fc0f33aa0f0e91e50e9921805)

pkgs/servers/web-apps/discourse/plugins/discourse-github/Gemfile.lock

@@ -1,21 +1,25 @@
 GEM
   remote: https://rubygems.org/
   specs:
-    addressable (2.7.0)
+    addressable (2.8.0)
       public_suffix (>= 2.0.2, < 5.0)
-    faraday (1.4.2)
+    faraday (1.5.0)
       faraday-em_http (~> 1.0)
       faraday-em_synchrony (~> 1.0)
       faraday-excon (~> 1.1)
+      faraday-httpclient (~> 1.0.1)
       faraday-net_http (~> 1.0)
       faraday-net_http_persistent (~> 1.1)
+      faraday-patron (~> 1.0)
       multipart-post (>= 1.2, < 3)
       ruby2_keywords (>= 0.0.4)
     faraday-em_http (1.0.0)
     faraday-em_synchrony (1.0.0)
     faraday-excon (1.1.0)
+    faraday-httpclient (1.0.1)
     faraday-net_http (1.0.1)
     faraday-net_http_persistent (1.1.0)
+    faraday-patron (1.0.0)
     multipart-post (2.1.1)
     octokit (4.21.0)
       faraday (>= 0.9)
@@ -27,11 +31,11 @@ GEM
       faraday (> 0.8, < 2.0)
 
 PLATFORMS
-  ruby
+  x86_64-linux
 
 DEPENDENCIES
   octokit (= 4.21.0)
   sawyer (= 0.8.2)
 
 BUNDLED WITH
-   2.1.4
+   2.2.20