Use annotate from rubygems

Gemfile

@@ -145,10 +145,11 @@ group :assets do
 end
 
 group :development do
-  gem "annotate", git: "https://github.com/ctran/annotate_models.git"
+  gem "annotate", "~> 2.6.0.beta2"
   gem "letter_opener"
   gem 'quiet_assets', '~> 1.0.1'
   gem 'rack-mini-profiler'
+
   # Better errors handler
   gem 'better_errors'
   gem 'binding_of_caller'

Gemfile.lock

-GIT
-  remote: https://github.com/ctran/annotate_models.git
-  revision: 18a4e2eb77c8f3ef695b563e4a7ca45dfede819b
-  specs:
-    annotate (2.6.0.beta2)
-      activerecord (>= 2.3.0)
-      rake (>= 0.8.7)
-
 GEM
   remote: https://rubygems.org/
   specs:
@@ -39,6 +31,9 @@ GEM
     acts-as-taggable-on (2.4.1)
       rails (>= 3, < 5)
     addressable (2.3.4)
+    annotate (2.6.0.beta2)
+      activerecord (>= 2.3.0)
+      rake (>= 0.8.7)
     arel (3.0.2)
     asciidoctor (0.1.3)
     awesome_print (1.2.0)
@@ -551,7 +546,7 @@ PLATFORMS
 
 DEPENDENCIES
   acts-as-taggable-on
-  annotate!
+  annotate (~> 2.6.0.beta2)
   asciidoctor
   awesome_print
   better_errors