[Bundle] Always add simplecov as a coveralls dependency.

Gemfile

@@ -18,6 +18,9 @@ group :development do
   gem 'prettybacon', :git => 'https://github.com/irrationalfab/PrettyBacon.git', :branch => 'master'
   gem "rake"
   gem 'coveralls', :require => false, :git => 'https://github.com/lemurheavy/coveralls-ruby.git'
+  # Explicitly add this, otherwise it might sometimes be missing:
+  # https://github.com/lemurheavy/coveralls-ruby/blob/master/coveralls-ruby.gemspec#L23.
+  gem 'simplecov'
 end
 
 group :debugging do

Gemfile.lock

@@ -119,6 +119,10 @@ GEM
     rest-client (1.6.7)
       mime-types (>= 1.16)
     ruby-prof (0.13.0)
+    simplecov (0.7.1)
+      multi_json (~> 1.0)
+      simplecov-html (~> 0.7.1)
+    simplecov-html (0.7.1)
     slop (3.4.5)
     term-ansicolor (1.2.2)
       tins (~> 0.8)
@@ -150,5 +154,6 @@ DEPENDENCIES
   rb-fsevent
   redcarpet (< 3.0.0)
   ruby-prof
+  simplecov
   xcodeproj!
   yard