Reorganised fixture.yml so it will be easy to plug in to the boid class.
Changed regression test, it runs but unfortunately it only passed for very very large delta. There may be a problem with my code which is making the velocity of the boids far too high.
Made the boid number and weight factor different inputs in the boid class methods in case that is the source of the problem.
Changed boids.py to account for the changes made to the boid class methods.