Fix missing SL4J class bug to be able to log inside UI

Added dependencies in client pom to make them available in the UI
because some classes of SL4J where missing in the resulting jar-file and
logging within the UI was not possible (always resulted in usage of the
NOPLogger).

Change-Id: Iecf598f0dfcbbb7fd75dc14b91877f94c414f48d
Signed-off-by: Denis Knoepfle <denis.knoepfle@sap.com>