Fine-tuning the juju-epc codebase for better error-handling

Fine-tuning the juju-epc codebase for better error-handling

The changes are mostly basic/cosmetic in nature.
 - Add some additional info in loggers.
 - Remove timeout from few commands(such as juju deploy)
 - Add exception logging for few commands(such as juju bootstrap).
 - Change rsync to cp for feature file transfer within ABot.

Change-Id: Ibeaae17f1c25d04b7830ed42719b70e6c99228cf
Signed-off-by: soumaya <soumaya.nayek@rebaca.com>
(cherry picked from commit a69c4be1d1b4c6cc5021a14e63c9f73d28490942)