Remove jekyll-admin

Gemfile

@@ -6,13 +6,13 @@ git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }
 
 gem "webrick"
 gem "jekyll"
+gem "rack", ">= 2.2.3"
 
 group :jekyll_plugins do
 	gem 'jekyll-katex'
   gem 'jekyll-sitemap'
   gem 'jekyll-feed'
   gem 'jekyll-seo-tag'
-  gem 'jekyll-admin'
   gem 'jekyll-minifier'
 end
 

Gemfile.lock

@@ -3,7 +3,6 @@ GEM
   specs:
     addressable (2.8.0)
       public_suffix (>= 2.0.2, < 5.0)
-    backports (3.21.0)
     colorator (1.1.0)
     concurrent-ruby (1.1.9)
     cssminify2 (2.0.1)
@@ -33,10 +32,6 @@ GEM
       rouge (~> 3.0)
       safe_yaml (~> 1.0)
       terminal-table (~> 2.0)
-    jekyll-admin (0.11.0)
-      jekyll (>= 3.7, < 5.0)
-      sinatra (~> 1.4)
-      sinatra-contrib (~> 1.4)
     jekyll-feed (0.15.1)
       jekyll (>= 3.7, < 5.0)
     jekyll-katex (1.0.0)
@@ -68,15 +63,10 @@ GEM
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
     mercenary (0.4.0)
-    multi_json (1.15.0)
     pathutil (0.16.2)
       forwardable-extended (~> 2.6)
     public_suffix (4.0.6)
-    rack (1.6.13)
-    rack-protection (1.5.5)
-      rack
-    rack-test (1.1.0)
-      rack (>= 1.0, < 3)
+    rack (2.2.3)
     rb-fsevent (0.11.0)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
@@ -85,20 +75,8 @@ GEM
     safe_yaml (1.0.5)
     sassc (2.4.0)
       ffi (~> 1.9)
-    sinatra (1.4.8)
-      rack (~> 1.5)
-      rack-protection (~> 1.4)
-      tilt (>= 1.3, < 3)
-    sinatra-contrib (1.4.7)
-      backports (>= 2.0)
-      multi_json
-      rack-protection
-      rack-test
-      sinatra (~> 1.4.0)
-      tilt (>= 1.3, < 3)
     terminal-table (2.0.0)
       unicode-display_width (~> 1.1, >= 1.1.1)
-    tilt (2.0.10)
     uglifier (4.2.0)
       execjs (>= 0.3.0, < 3)
     unicode-display_width (1.7.0)
@@ -109,12 +87,12 @@ PLATFORMS
 
 DEPENDENCIES
   jekyll
-  jekyll-admin
   jekyll-feed
   jekyll-katex
   jekyll-minifier
   jekyll-seo-tag
   jekyll-sitemap
+  rack (>= 2.2.3)
   webrick
 
 BUNDLED WITH