#registerTask(): add function to array

[eddiemonge]

registered task is array and task is function.

• Convert array to a function call
• Add grunt.task.run(existingTasks) to function call
• Append function task to function call

See https://github.com/bezoerb/gruntfile-api/tree/master#register-task for reference

Before:

grunt.registerTask('build', [
  'task1',
  'task2',
  'task3'
]);

After:

grunt.registerTask('build', function(target) {
  grunt.task.run([
    'task1',
    'task2',
    'task3'
  ]);
  // new custom function task
});