Improve test coverage

[chris48s]

Starting here:

ckanext-ddi/ckanext/ddi/tests/test_blueprints.py

Lines 128 to 140 in da110a2

	"""
	def test_form_submit_success_xml_file_from_url(
	self, app, monkeypatch, tmpdir, ckan_config
	):
	_patch_storage_path(monkeypatch, tmpdir, ckan_config)
	# TODO: test importing from a URL, mock the HTTP requests with responses
	def test_form_submit_success_xml_and_rdf_files_from_urls(
	self, app, monkeypatch, tmpdir, ckan_config
	):
	_patch_storage_path(monkeypatch, tmpdir, ckan_config)
	# TODO: test importing from URLs, mock the HTTP requests with responses
	"""

We should also have some more robust tests for the importer/metadata modules. At the moment all of our tests are processing one example file which doesn't really exercise the full range of execution paths there.