Remove debug gem (it causes issues on MRI 1.9.3).

Gemfile

@@ -49,7 +49,6 @@ end
 
 group :development do
   gem 'mongrel', '>= 1.2.0.pre2'
-  gem 'ruby-debug19', :require => 'ruby-debug'
   gem 'pry'
   gem 'pry-rails'
   gem 'pry-doc'

Gemfile.lock

@@ -40,7 +40,6 @@ GEM
       i18n (~> 0.6)
       multi_json (~> 1.0)
     addressable (2.2.8)
-    archive-tar-minitar (0.5.2)
     arel (3.0.2)
     bcrypt-ruby (3.0.1)
     bourbon (2.1.0)
@@ -75,7 +74,6 @@ GEM
       coffee-script-source
       execjs
     coffee-script-source (1.3.3)
-    columnize (0.3.6)
     daemons (1.0.10)
     database_cleaner (0.8.0)
     devise (2.1.0)
@@ -146,8 +144,6 @@ GEM
     libv8 (3.3.10.4)
     libwebsocket (0.1.3)
       addressable
-    linecache19 (0.5.12)
-      ruby_core_source (>= 0.1.4)
     listen (0.4.2)
       rb-fchange (~> 0.0.5)
       rb-fsevent (~> 0.9.1)
@@ -287,18 +283,8 @@ GEM
       activesupport (>= 3.0)
       railties (>= 3.0)
       rspec (~> 2.10.0)
-    ruby-debug-base19 (0.11.25)
-      columnize (>= 0.3.1)
-      linecache19 (>= 0.5.11)
-      ruby_core_source (>= 0.1.4)
-    ruby-debug19 (0.11.6)
-      columnize (>= 0.3.1)
-      linecache19 (>= 0.5.11)
-      ruby-debug-base19 (>= 0.11.19)
     ruby-openid (2.1.8)
     ruby-progressbar (0.0.10)
-    ruby_core_source (0.1.5)
-      archive-tar-minitar (>= 0.5.2)
     rubyzip (0.9.8)
     sass (3.1.19)
     sass-rails (3.2.5)
@@ -393,7 +379,6 @@ DEPENDENCIES
   redcarpet (~> 2.1.0)
   resque (~> 1.19)
   rspec-rails
-  ruby-debug19
   sass-rails (~> 3.2.3)
   simplecov (~> 0.6.4)
   styx (~> 0.1.0)