Add model to represent VfModuleModel and Artifact management

. add VfModuleModel to represent content of VfModule
. add Gsonutil to support List which is the content of Vf
  Module meta json
. add CloudArtifact to deal with Artifact for subplug action
. Fix pom.xml typo

Change-Id: Ic459118323bf50939493b0f0feff7ba96dd9a64d
Issue-ID: MULTICLOUD-511
Signed-off-by: liboNet <libo.zhu@intel.com>
4 files changed