Wait for tuskar-api to start up

tuskar-ui runs immediately after tuskar-api. There is a chance
that the api has not come up completely before 101-tuskar-ui runs.
This patch adds a five second wait if tuskar-api is found to be
not running.

Change-Id: I5c9ff917d7f24b704e17d336cc1f79d211abd0a9
Closes-Bug: 1394430
Merge "Wait for tuskar-api to start up"