Sporadic health-check failures for `test_regular_mapping`

[abingham]

I've seen a Hypothesis health-check failure related to slow data generation for test_catalog.TestCatalogBuilder.test_regular_mapping on a few occasions. I've seen it both locally and on travis. It doesn't happen with every build, and it looks like this:

self = <test.test_catalog.TestCatalogBuilder object at 0x110ef3cf8>

    @given(start=integers(),
>          num=integers(0, 1000),
           step=integers(-1000, 1000),
           values=data())
    def test_regular_mapping(self, start, num, step, values):
E   hypothesis.errors.FailedHealthCheck: Data generation is extremely slow: Only produced 8 valid examples in 1.07 seconds (0 invalid ones and 0 exceeded maximum size). Try decreasing size of the data you're generating (with e.g.max_size or max_leaves parameters).
E   See https://hypothesis.readthedocs.io/en/latest/healthchecks.html for more information about this. If you want to disable just this health check, add HealthCheck.too_slow to the suppress_health_check settings for this test.

test/test_catalog.py:71: FailedHealthCheck

[rob-smallshire]

I think these are sorted now. I'll close this issue.