Common: Added notification entity for mail notifier.
Common: Added notification entity for mail notifier.

Change-Id: I2286f2fedb1be0c26025e57fe98ec4c626a51864
Signed-off-by: nnDarshan <d2c6d450ab98b078f2f1942c995e6d92dd504bc8@gmail.com>

skyrings/skyring-common,skyrings/skyring-common