Introduce mini_racer in therubyracer's place

Gemfile

@@ -9,7 +9,7 @@ gem 'sass-rails'
 
 gem 'uglifier'
 gem 'coffee-rails'
-gem 'therubyracer', platforms: :ruby
+gem 'mini_racer', platforms: :ruby
 gem 'jquery-rails'
 
 gem 'slim-rails'

Gemfile.lock

@@ -169,7 +169,7 @@ GEM
       railties (>= 4.2.0)
       thor (>= 0.14, < 2.0)
     json (1.8.3)
-    libv8 (3.16.14.15)
+    libv8 (5.1.281.59.1)
     listen (3.1.5)
       rb-fsevent (~> 0.9, >= 0.9.4)
       rb-inotify (~> 0.9, >= 0.9.7)
@@ -184,6 +184,8 @@ GEM
     mimemagic (0.3.2)
     mini_magick (4.5.1)
     mini_portile2 (2.1.0)
+    mini_racer (0.1.4)
+      libv8 (~> 5.1)
     minitest (5.9.1)
     morrisjs-rails (0.5.1)
       railties (> 3.1, < 5)
@@ -258,7 +260,6 @@ GEM
     rb-fsevent (0.9.7)
     rb-inotify (0.9.7)
       ffi (>= 0.5.0)
-    ref (2.0.0)
     refile (0.6.2)
       mime-types
       rest-client (~> 1.8)
@@ -345,9 +346,6 @@ GEM
       tins (~> 1.0)
     terminal-table (1.7.3)
       unicode-display_width (~> 1.1.1)
-    therubyracer (0.12.2)
-      libv8 (~> 3.16.14.0)
-      ref
     thor (0.19.1)
     thread (0.2.2)
     thread_safe (0.3.5)
@@ -397,6 +395,7 @@ DEPENDENCIES
   jbuilder
   jquery-datatables-rails
   jquery-rails
+  mini_racer
   morrisjs-rails
   nested_form
   pg
@@ -420,7 +419,6 @@ DEPENDENCIES
   spring
   spring-commands-rspec
   sqlite3
-  therubyracer
   uglifier
   yaml_db