Removes 'ENV['RAILS_ENV']=='test' from railtie.rb (#114)

The hard-coded check in https://github.com/metaskills/minitest-spec-rails/blob/master/lib/minitest-spec-rails/railtie.rb#L6 made it impossible to use specs in custom testing environments. 

Instead of hard-coding this, it makes more sense to include the code whenever the gem is loaded. (i.e. using the groups in the Gemfile).

lib/minitest-spec-rails/railtie.rb

@@ -3,32 +3,30 @@ class Railtie < ::Rails::Railtie
  config.minitest_spec_rails = ActiveSupport::OrderedOptions.new
  config.minitest_spec_rails.mini_shoulda = false
 
- if ENV['RAILS_ENV'] == 'test'
- config.before_initialize do |_app|
- require 'active_support'
- require 'minitest-spec-rails/init/active_support'
- require 'minitest-spec-rails/parallelize'
- ActiveSupport.on_load(:action_controller) do
- require 'minitest-spec-rails/init/action_controller'
- require 'minitest-spec-rails/init/action_dispatch'
- end
- ActiveSupport.on_load(:action_mailer) do
- require 'minitest-spec-rails/init/action_mailer'
- end
- ActiveSupport.on_load(:active_job) do
- require 'minitest-spec-rails/init/active_job'
- end
+ config.before_initialize do |_app|
+ require 'active_support'
+ require 'minitest-spec-rails/init/active_support'
+ require 'minitest-spec-rails/parallelize'
+ ActiveSupport.on_load(:action_controller) do
+ require 'minitest-spec-rails/init/action_controller'
+ require 'minitest-spec-rails/init/action_dispatch'
  end
-
- initializer 'minitest-spec-rails.action_view', after: 'action_view.setup_action_pack', group: :all do |_app|
-  ActiveSupport.on_load(:action_view) do
-  require 'minitest-spec-rails/init/action_view'
- end
+ ActiveSupport.on_load(:action_mailer) do
+  require 'minitest-spec-rails/init/action_mailer'
+ end
+ ActiveSupport.on_load(:active_job) do
+ require 'minitest-spec-rails/init/active_job'
  end
+ end
 
- initializer 'minitest-spec-rails.mini_shoulda', group: :all do |app|
- require 'minitest-spec-rails/init/mini_shoulda' if app.config.minitest_spec_rails.mini_shoulda
+ initializer 'minitest-spec-rails.action_view', after: 'action_view.setup_action_pack', group: :all do |_app|
+ ActiveSupport.on_load(:action_view) do
+ require 'minitest-spec-rails/init/action_view'
  end
  end
+
+ initializer 'minitest-spec-rails.mini_shoulda', group: :all do |app|
+ require 'minitest-spec-rails/init/mini_shoulda' if app.config.minitest_spec_rails.mini_shoulda
+ end
  end
 end