Switching to mpc-wbc-cpp library instead of example-adder

CMakeLists.txt

include/mpc-wbc-cpp/MPC.hpp

include/mpc-wbc-cpp/Planner.hpp

include/mpc-wbc-cpp/gepadd.hpp

python/example_adder/__init__.py

python/gepadd.cpp

python/mpc_wbc_cpp/__init__.py

src/MPC.cpp

src/Planner.cpp

src/gepadd.cpp

src/main.cpp

tests/add.cpp

tests/boost_add.cpp

tests/python/test_add.py