Header: Initial PlanningPoker module with GUI is created

The basic GUI for PlanningPoker module was implemented.

Reported by: Batyrlan Nurbekov
Signed-off-by: Batyrlan Nurbekov <bnurbekov@wpi.edu>
Merge pull request #6 from bnurbekov/dev-ppoker

Header: Initial PlanningPoker module with GUI is created