define as private GanttHelperTest helper methods

git-svn-id: http://svn.redmine.org/redmine/trunk@12787 e93f8b46-1217-0410-a6f0-8f06a7374b81
replace shoulda context "#number_of_rows" at GanttHelperTest

git-svn-id: http://svn.redmine.org/redmine/trunk@12788 e93f8b46-1217-0410-a6f0-8f06a7374b81
replace shoulda context "#number_of_rows_on_project" at GanttHelperTest

git-svn-id: http://svn.redmine.org/redmine/trunk@12789 e93f8b46-1217-0410-a6f0-8f06a7374b81
replace shoulda context "#subjects" at GanttHelperTest

git-svn-id: http://svn.redmine.org/redmine/trunk@12790 e93f8b46-1217-0410-a6f0-8f06a7374b81
Rails4: fix "assert_template 'form'" fails at IssuesControllerTest

git-svn-id: http://svn.redmine.org/redmine/trunk@12791 e93f8b46-1217-0410-a6f0-8f06a7374b81
use escaped "can't" constant at TrackersControllerTest

git-svn-id: http://svn.redmine.org/redmine/trunk@12792 e93f8b46-1217-0410-a6f0-8f06a7374b81
define constant of escaped "Can't" for tests

git-svn-id: http://svn.redmine.org/redmine/trunk@12793 e93f8b46-1217-0410-a6f0-8f06a7374b81
use escaped "Can't" constant at TrackersControllerTest

git-svn-id: http://svn.redmine.org/redmine/trunk@12794 e93f8b46-1217-0410-a6f0-8f06a7374b81