During review of DM-7297 (porting ip_diffim to py3), we found the examples and tests needed more attention. Some specifics to start:

• There are three test files in the examples and it's unclear why (`compareKernelTypes`, `compareLambdaTypes`, and `jackknifeResampleSpatialKernel`)
• The `compareLambdaTypes` example uses `afwdata` but should catch the exception if `afwdata` is missing and then skip the tests. It also has old-style tests with `suite.`
• There are lots of try/except/else blocks in `testBasisLists` (and other tests too!) that would be cleaner using a `with self.assertRaises(Exception)` syntax. tjenness says: "I think this entire construct exists to convert an 'E' test error into an 'F' test failure ... I would be inclined to remove all the boilerplate and let any problems trigger an 'E' because these commands are all meant to work and an 'E' is still something that needs to be fixed. There's a reason why there is no `self.assertDoesNotRaise()` method in `unittest`."