PMD just released a big new major version, 7.0.0. This makes a fairly

large change to the basic command-line UI, but is mostly otherwise

compatible.
Some of the output is slightly different for a few of the tests. I've

changed the simulation tests to simulate PMD7, and the integration tests

sometimes need to conditionalize the expected output. We also had one

test (for a config file with no rules) that was obsolete even in PMD

6.55, which treated a file with no active rules as a warning rather than

an error.

Ran unit tests with both PMD 6.55.0 and 7.0.0. Saw that everything

passed.