Fix multiple instances and no method 'async' bug}
closes #28 closes #30 - added stopdone to wait for server to stop - renamed done to startdone - added conditional for `grunt.task.current.async()` - added testsequence which is able to reproduce the bug without my changes to server.js - added `express:defaults` without `express:defaults:stop` at the end of the file to reproduce missing 'async'