Ensure that the correct Bundler is used to run acceptance tests

spec/support/acceptance/helpers/command_helpers.rb

@@ -39,14 +39,7 @@ module AcceptanceTests
 
     def run_command_within_bundle(*args)
       run_command_isolated_from_bundle(*args) do |runner|
-        bundler_version = `bundle -v`.sub(/Bundler version /, '')
-
-        if bundler_version !~ /^1\./
-          puts 'Installing Bundler 1.x...'
-          system('gem', 'install', 'bundler', '-v', '~> 1')
-        end
-
-        runner.command_prefix = 'bundle exec'
+        runner.command_prefix = "bundle _#{bundle.version}_ exec"
         runner.env['BUNDLE_GEMFILE'] = fs.find_in_project('Gemfile').to_s
 
         yield runner if block_given?

spec/support/tests/bundle.rb

@@ -55,6 +55,10 @@ module Tests
       end
     end
 
+    def version
+      Bundler::VERSION
+    end
+
     protected
 
     attr_reader :fs