Allow interactive jasmine specs for vagrant devs

This is in the running for tiniest PR but it might be useful for vagrant devs.

This will allow a vagrant dev to run 'rake jasmine' in the vagrant vm and then on the host machine visit http://localhost:3004 and interactively view (and debug) jasmine specs.

I wasn't sure about the rationale for choosing other ports for the host machine port-forwarding (security?) so if 8888 on the host (which is the default and what prints in the terminal) seems more natural for the jasmine server, then let me know.