Added set_current_revision task
Added set_current_revision task

New version of capistrano rely on set_current_revision task. Here it just do nothing.
wercker/capistrano-scm-copy,izzm/capistrano-scm-copy,hkroger/capistrano-scm-copy,liepa/capistrano-scm-copy,vanburg/capistrano-scm-copy,dmvieira/capistrano-scm-copy