pass everything in colcon test, with the exception of a copyright statement

The package should pass colcon test, or we should remove the tests from the CMakeLists.txt. Upon running colcon test, there were a bunch of tabs in the source code so it picked up on something good!

@cflanagan up to you if you want to merge this now or after assignment 1 is done, I don't mind. I've also added initialization of the variables in wall_follower.hpp, which would be good for current students to have.

I've tested that the robot moves around the map fine in Gazebo.

Signed-off-by: ijnek kenjibrameld@gmail.com