Improve 'fluo list' command to print Fluo application start time

Improve upon the basic output of the fluo list command below by adding the start time of the Fluo application. Below is the output of current list

$ fluo list
Fluo instance (localhost/fluo) contains 2 application(s)

Application     Status     # Workers
-----------     ------     ---------
test1           RUNNING        1
test2           STOPPED        0

One way to implement this to create a getStartTime() method in FluoAdminImpl that determines minimum creation time of Zookeeper paths (ZookeeperPath.ORACLE_SERVER and all children of ZookeeperPath.FINDERS) to determine when the Fluo application was started. The existence of these paths in Zookeeper are currently used in FluoAdminImpl to determine if oracle and workers are running. In FluoList, the getStartTime() could be called if the application is running and the time printed out in a new column.

[keith-turner]

@mikewalch will you be able to provide @srikailash with assistance on this issue? If not, I may be able to.

[keith-turner]

There are definitely alot of concurrency issues with trying to keep an accurate start time. It would probably be possible to work out an algorithm using Zookeeper atomic compare and set features to maintain this information. However I do no think its worthwhile. May want to consider closing the issue or reframing it to listing the oldest running process start time instead of the app start time.