Add rake to Gemfile

Gemfile

@@ -1,6 +1,7 @@
 source 'https://rubygems.org'
 ruby '2.2.0'
 
+gem 'rake'
 gem 'thor'
 gem 'pry', '~> 0.10.0'
 gem 'activesupport', '~> 4.0', require: false

Gemfile.lock

@@ -51,6 +51,7 @@ GEM
       rack
     rack-test (0.6.3)
       rack (>= 1.0)
+    rake (10.4.2)
     rr (1.1.2)
     sass (3.4.12)
     sinatra (1.4.5)
@@ -105,6 +106,7 @@ DEPENDENCIES
   pry (~> 0.10.0)
   rack
   rack-test
+  rake
   rr
   sass
   sinatra