Coverage update

[WrathfulSpatula]

I haven't checked coverage, lately, which should always be a priority for us. Largely, I know most new optimizations have been refactors of already-covered code, but the numbers have likely dropped. (Specifically, IndexedLDA/ADC/SBC are probably not fully covered by existing tests, for example.) This issue is to put checking and updating coverage on my calendar, for this weekend, at least if no obvious avenues to improvements are clear, (but higher priority than that).

[WrathfulSpatula]

Instructions on how to test coverage are in the README, and I am happy to help any takers, for the Unitary Hack bounty. The goal is >95% coverage; if coverage is already above 95%, let's make an honest effort to get as reasonably close to 99% or 100% as we can.

[WrathfulSpatula]

Note that unitaryHACK contributors are not responsible for bugs that may be uncovered in expanding coverage. Between random mirror circuit tests, tests adapted from Qiskit in Python, and several other test suites applied over our external plugins, the real total coverage probably precludes many nasty surprises in the core gate methods, but you're free to write tests that show a method is broken and pass them to me, the maintainer, to fix the core implementation.