fix a resolution issue and add a test for it

lib/guard/rails.rb

@@ -16,7 +16,7 @@ module Guard
         :force_run => false
       }.merge(options)
 
-      @runner = Guard::RailsRunner.new(options)
+      @runner = RailsRunner.new(options)
     end
 
     def start

spec/lib/guard/rails_spec.rb

@@ -2,6 +2,14 @@ require 'spec_helper'
 require 'guard/rails'
 
 describe Guard::Rails do
+  let(:guard) { Guard::Rails.new(watchers, options) }
+  let(:watchers) { [] }
+  let(:options) { {} }
 
+  describe '#initialize' do
+    it "should initialize with options" do
+      guard
+    end
+  end
 end