Update assertions for 'git:check' test scenario

Capistrano 'git:check' task executes a `git ls-remote -h #{repo_url}`
command to check if remote repo is accessible. If successful, command
output is a list of references and their SHAs.

Task should be successful and we're pretty sure remote repo will have a
`master` reference, so that's what we're asserting.

We're NOT asserting:
 * repo references other than master - likely to change
 * reference SHAs - will definitely change

CHANGELOG.md

@@ -73,6 +73,7 @@ Breaking Changes:
   * Improved the output of `cap --help`. (@mbrictson)
   * Cucumber suite now runs on the latest version of Vagrant (@tpett)
   * The `ask` method now supports the `echo: false` option. (@mbrictson, @kaikuchn)
+  * Cucumber scenario improvements (@bruno-)
   * Added suggestion to Capfile to use 'capistrano-passenger' gem, replacing suggestion in config/deploy.rb to re-implement 'deploy:restart' (@betesh)
   * Updated svn fetch_revision method to use `svnversion`
 

features/deploy.feature

@@ -6,7 +6,8 @@ Feature: Deploy
 
   Scenario: Creating the repo
     When I run cap "git:check"
-    Then references in the remote repo are listed
+    Then the task is successful
+    And references in the remote repo are listed
 
   Scenario: Creating the directory structure
     When I run cap "deploy:check:directories"

features/step_definitions/assertions.rb

@@ -1,4 +1,5 @@
 Then(/^references in the remote repo are listed$/) do
+  expect(@output).to include('refs/heads/master')
 end
 
 Then(/^the shared path is created$/) do

features/step_definitions/cap_commands.rb

@@ -1,5 +1,5 @@
 When(/^I run cap "(.*?)"$/) do |task|
-  @success = TestApp.cap(task)
+  @success, @output = TestApp.cap(task)
 end
 
 When(/^I run cap "(.*?)" as part of a release$/) do |task|