Add CH3OH frequency job to unit tests or regressions

[langner]

This is branched from #281, which was supposed to expand the standard cclib test suite to include anharmonic frequency calculations and constrained scan calculations.

Some points:

• We'll want to rerun this in g16 which is the newest test suite.
• This job has opt instead of freq which I think was the intention, so that needs to be changed.
• We were supposed to parse vibanharms from this.

ch3oh-freq.com.gz ch3oh-freq.fchk.gz ch3oh-freq.g09.gz

[langner]

@berquist Do you think it's worthwhile to rerun this in g16, with freq and add it to unit tests?

[berquist]

Maybe, but

• We will need to decide on anharmonic frequency attributes.
• The files are not all right. The com file has the wrong input.
• We should do this after standardizing on geometries (https://github.com/cclib/cclib/issues/407) and methods (https://github.com/cclib/cclib/issues/296, https://github.com/cclib/cclib/issues/136), at least changing this to water.