Add "karma:unit:start" to "grunt serve" task

If you run the "grunt serve" task and then edit a file, this error pops up:

There is no server listening on port 8080
Warning: Task "karma:unit:run" failed. Use --force to continue.

Aborted due to warnings.


Adding "karma:unit:start" to the "grunt serve" task resolves the issue (every time i edit a file, tests are executed correctly).

P.S.: thanks for your generator, very nice job!