added heading function to test yaw alignment

src/CMakeLists.txt

 # driver source files
 SET(sources common_fc.cpp kinematics.cpp uam_task_ctrl.cpp)
-SET(sources_tasks tasks/ir.cpp tasks/vs.cpp tasks/cog.cpp tasks/jl.cpp tasks/eepos.cpp)
+SET(sources_tasks tasks/ir.cpp tasks/vs.cpp tasks/cog.cpp tasks/jl.cpp tasks/eepos.cpp tasks/heading.cpp)
 
 # application header files
 SET(headers common_obj.h common_fc.h kinematics.h uam_task_ctrl.h)
-SET(headers_tasks tasks/ir.h tasks/vs.h tasks/cog.h tasks/jl.h tasks/eepos.h)
+SET(headers_tasks tasks/ir.h tasks/vs.h tasks/cog.h tasks/jl.h tasks/eepos.h tasks/heading.h)
 
 # locate the necessary dependencies