Add a CI Workflow for System Tests

[john-science]

ARMI provides some end-to-end tests in the form of Jupyter notebooks, that are run during unit testing. They serve several purposes, among them they are examples in the docs that we want to make sure are still working.

But they also serve as some end-to-end tests, the best ARMI can do without external physics kernels. As such, we should move them into their own CI channel, so we can see them on their own.

armi/armi/tests/test_notebooks.py

Lines 34 to 42 in 3431c44

	class NotebookTests(unittest.TestCase):
	def test_runParamSweep(self):
	runNotebook(os.path.join(TUTORIALS, "param_sweep.ipynb"))
	def test_runDataModel(self):
	runNotebook(os.path.join(TUTORIALS, "data_model.ipynb"))
	# Do some cleanup because some code run in the notebook doesn't honor the
	# TempDirectoryChanger
	os.remove(os.path.join(TUTORIALS, "anl-afci-177.h5"))

NOTE: This would also be a good time to move these data files to armi/testing/resources/ or something similar.