Test kubernetes in CI

[benclifford]

This PR is a codification of what I had to do to get pytest passing for myself while trying to review other kubernetes PRs.

The bulk of the modified files are additional test markings to label which tests require a shared filesystem (between all workers and the submit side) to store working files; and which tests require file staging (as the default file staging configuration is not valid for kubernetes, due to lack of shared file system).

There is also a bugfix for default pod names being generated as invalid format (which can fixed by users by specifying an explicit prefix)

This PR can probably be merged into master in a few stages.

[benclifford]

this is failing repeatedly on this test: (at 5c55fe6)

parsl/tests/test_regression/test_226.py F
=================================== FAILURES ===================================
__________________________________ test_no_eq __________________________________
    def test_no_eq():
>       res = get_foo_x('foo').result()

(most recently with a ManagerLost... before that, I wasn't capturing enough logging to see the whole exception.