Move development dependencies into Gemfile

Gemfile

@@ -1,7 +1,19 @@
 source 'https://rubygems.org'
 
-platforms :jruby do
-  gem 'jruby-openssl', '~> 0.7'
+gem 'jruby-openssl', :platforms => :jruby
+gem 'rake'
+gem 'yard'
+
+group :development do
+  gem 'kramdown'
+  gem 'pry'
+  gem 'pry-debugger', :platforms => :mri_19
+end
+
+group :test do
+  gem 'rspec'
+  gem 'simplecov'
+  gem 'webmock'
 end
 
 gemspec

mtgox.gemspec

@@ -5,13 +5,6 @@ Gem::Specification.new do |gem|
   gem.add_dependency 'faraday', '~> 0.8'
   gem.add_dependency 'faraday_middleware', '~> 0.8'
   gem.add_dependency 'multi_json', '~> 1.3'
-  gem.add_development_dependency 'json'
-  gem.add_development_dependency 'maruku'
-  gem.add_development_dependency 'rake'
-  gem.add_development_dependency 'rspec'
-  gem.add_development_dependency 'simplecov'
-  gem.add_development_dependency 'webmock'
-  gem.add_development_dependency 'yard'
   gem.author      = "Erik Michaels-Ober"
   gem.description = %q{Ruby wrapper for the Mt. Gox Trade API. Mt. Gox allows you to trade US Dollars (USD) for Bitcoins (BTC) or Bitcoins for US Dollars.}
   gem.email       = 'sferik@gmail.com'