Switch unit tests to the context manager form of assertRaisesMessage.
Review Request #10293 — Created Oct. 30, 2018 and submitted — Latest diff uploaded
We have a lot of older unit tests that use the lambda form of
assertRaisesMessage, which is a bit more annoying to work with. This
was needed for older Python support. In preparation for some other
unit test changes, this change performs some cleanup on these calls,
switching to the context manager form in all calls.
Unit tests pass.