fix `ci-status` showing the latest status

GitHub API seems to return statuses in reverse-chronological order. The
first one is the latest one.

Fixes #327

features/ci_status.feature

@@ -16,8 +16,8 @@ Feature: hub ci-status
     Given there is a commit named "the_sha"
     Given the remote commit states of "michiels/pencilbox" "the_sha" are:
       """
-      [ { :state => 'pending' },
-        { :state => 'success' }  ]
+      [ { :state => 'success' },
+        { :state => 'pending' }  ]
       """
     When I run `hub ci-status the_sha`
     Then the output should contain exactly "success\n"

lib/hub/commands.rb

@@ -88,7 +88,7 @@ module Hub
       end
 
       statuses = api_client.statuses(head_project, sha)
-      status = statuses.last
+      status = statuses.first
       ref_state = status ? status['state'] : 'no status'
 
       exit_code = case ref_state