Release version 2.1.0

Release version 2.1.0

Changes:
 - Fix ToString bug
 - Fix pkgmgr client is not cleared bug
 - Apply mockup framework to gtest
 - Replace internal Bundle with tizen_base::Bundle
 - Remove unnecessary GetInst
 - Remove unnecessary exception handling codes
 - Remove duplicate codes
 - Remove mock objects
 - Fix apply not exist allow list bug
 - Handling OOM error
 - Add is_valid TCs
 - Fix memory leak
 - Remove unnecessary initialize
 - Remove unused value

Change-Id: I20532faffabf2d57a4a03b63a1b7ddbd09145c75
Signed-off-by: hyunho <hhstark.kang@samsung.com>