Use the correct filename of the method selectors.
Use the correct filename of the method selectors.

Without that, cargo always thinks the project is dirty and recompile everything.

Fix #6.

steveklabnik/ncollide,MichaelRiss/ncollide,steveklabnik/ncollide,sebcrozet/ncollide,MichaelRiss/ncollide,sebcrozet/ncollide