Use random generated port instead of default
Use random generated port instead of default

[#159504657](https://www.pivotaltracker.com/story/show/159504657)

Signed-off-by: John Shahid <d5f6a919b5b5e6a4f7f09f1adf45e90e5c38b58e@gmail.com>

cloudfoundry-incubator/file-server