Added makefile for common commands

Makefile

+.PHONY: default
+default: plots animation
+
+
+assignment_fitness_vs_gen.png: plots
+
+assignment_survivors_vs_gen.png: plots
+
+.PHONY: plots
+plots: assignment_plots.py assignment_simulation_histories.p
+	python $<
+
+.PHONY: animation
+animation: assignment_anim.py assignment_simulation_histories.p
+	python $<
+
+assignment_simulation_histories.p: assignment_sim.py
+	python $<
+
+.PHONY: speedup
+speedup:
+	python speedup.py
+	
+