Export JIRA_TEST_IDS as env var

[grssmnn]

Hi,
I needed a simple interface for accessing the provided Jira test IDs in the test methods for logging purposes.
Therefore I added pytest_runtest_setup to the plugin so the test IDs are exported before every test run.

[fundakol]

You can achieve same result just from your tests. No need to include this code to the plugin.
I would use a fixture for that instead of keeping ids in an environment variable. It could be implemented like that:

@pytest.fixture
def jira_ids(request):
    markers = request.node.get_closest_marker('xray')
    if isinstance(markers.args[0], list):
        return markers.args[0]
    return [markers.args[0]]

def test_foo(jira_ids):
    ...