add racer

Gemfile

@@ -7,6 +7,7 @@ gem 'uglifier', '>= 1.3.0'
 gem 'coffee-rails', '~> 4.1.0'
 gem 'jquery-rails'
 gem 'jbuilder', '~> 2.0'
+gem "therubyracer"
 group :development, :test do
   gem 'byebug'
 end

Gemfile.lock

@@ -177,6 +177,7 @@ GEM
       activesupport (>= 3.0.0)
     launchy (2.4.3)
       addressable (~> 2.3)
+    libv8 (3.16.14.13)
     listen (3.0.6)
       rb-fsevent (>= 0.9.3)
       rb-inotify (>= 0.9.7)
@@ -249,6 +250,7 @@ GEM
     rb-fsevent (0.9.7)
     rb-inotify (0.9.7)
       ffi (>= 0.5.0)
+    ref (2.0.0)
     responders (2.1.2)
       railties (>= 4.2.0, < 5.1)
     rspec (3.4.0)
@@ -307,6 +309,9 @@ GEM
     sshkit (1.9.0)
       net-scp (>= 1.1.2)
       net-ssh (>= 2.8.0)
+    therubyracer (0.12.2)
+      libv8 (~> 3.16.14.0)
+      ref
     thor (0.19.1)
     thread_safe (0.3.5)
     tilt (2.0.2)
@@ -371,6 +376,7 @@ DEPENDENCIES
   spring
   spring-commands-rspec
   sqlite3
+  therubyracer
   uglifier (>= 1.3.0)
   web-console (~> 2.0)