Update formatting of existing tests in BamQc.t
Add ErrorRate tests to BamQc.t
Don't run ErrorRate if aligning with bsmap
Use Set::Scalar to make an aligner blacklist
Clean up _should_run_error_rate_for_pp.

It's valid to pass undef to Set::Scalar::has() so there's no reason to
check for it.
Merge pull request #260 from iferguson90/no-errorrate-with-bsmap

No errorrate with bsmap