Fix some ETSConfig and test nits

[mdickinson]

Fix some nits noticed during reviewing #1670. (But sufficiently unrelated to #1670 that I couldn't justify squeezing them into that PR.)

• Fix weird docstring end-quote indentations
• Fix overriding of TestCase.run, which implicitly assumes that we'll be using unittest as our test runner.
• Fix another test that assumed that the test runner would be unittest.