BHT unit test

jobs/src/bht_algorithm.py

jobs/src/bht_algorithm_2d.py

jobs/tests/__init__.py

jobs/tests/test_a_job.py

jobs/tests/test_bht_algorithm.py

jobs/tests/test_integrator.py

jobs/tests/test_jpl_data_query.py

jobs/unittests/test_bht_algorithm.py

jobs/unittests/test_integrator.py

tasks/bht/2D/bht_quad.py

tasks/bht/3D/bht_oct.py

tasks/bht/3D/galaxysimulation.py

tasks/bht/3D/simulate.py