**Tasks** - [x] Clean code files ([bellman_ford.c](https://github.com/codeSG/pgrouting/blob/bf-negative/src/bellman_ford/bellman_ford.c) , [bellman_ford_driver.cpp](https://github.com/codeSG/pgrouting/blob/bf-negative/src/bellman_ford/bellman_ford_driver.cpp), [pgr_bellman_ford.hpp](https://github.com/codeSG/pgrouting/blob/bf-negative/include/bellman_ford/pgr_bellman_ford.hpp)) - [x] Remove debug statements - [x] Remove unnecessary code
