setting seed on optimization and keep it in the results
Merge branch 'devel' into heuristic_methods
test with seeded data
Merge branch 'devel' into heuristic_methods

Conflicts:
	tests/test_strain_design_heuristics.py
setting travis to run multiprocess
Added seeded results for testing.
run heuristic tests on sequential view
Merge pull request #3 from biosustain/heuristic_methods

Heuristic methods use seed instead of pre-given random.