Add getAromaticResonanceIsomers() function to add the aromatic form to a molecule's resonance forms.
Make aromatic tests not work in progress by testing the resonance isomers.
Revert calculateCyclicSymmetryNumber() function now that aromatic form is a resonance isomer.

Also the algorithm in this function was only working for benzene but not others.
Create getSymmetryNumber() function for species object.

Returns the largest symmetry number amongst all resonance isomers.  This will return
the aromatic species' symmetry number if that is the largest one.
Change some symmetry tests to Total symmetry tests.
Changing the titles of some symmetry unit tests.

These get reported in the test log.
Merge remote-tracking branch 'greengroup/aromaticity' to get Aromatic isomers!

This closes pull request #322.

Here are @Connie's notes from that pull request:

    Implement a getAromaticResonanceIsomers() function in the Molecule
    class to make the aromatic form as a resonance isomer in Species
    objects. This will have similar consequences as Java where the aromatic
    resonance isomer's thermo can take on Cb group additivity values and
    give a more stable thermo value, which ultimately gets used by the
    species.

    I've taken out the aromaticity check in the
    calculateCyclicSymmetryNumber function in favor of making it a
    resonance isomer. We need the Cb bonds for thermo group addivitiy even
    more so than for symmetry number, and also now symmetry number will be
    calculated correctly ("more" correctly than before) for the aromatic
    resonance form and therefore produce the correct entropy.

    Some notes:

    The aromaticity perception is done by converting to an rdkitmol and
    then changing the bond and atomtypes in the resonance form. Like in
    RMG-Java, we restrict converting to B bonds to 6-membered rings which
    are carbon-only. This means that no aromatics containing heteroatoms
    are converted. We simply do not have the right atomtypes to support
    this right now.

    Some compounds such as Benzyne are aromatic but cause
    problems because the pi bond is in fact a triple bond, and carbon
    cannot handle having both a B bond and triple bond present. Therefore,
    only 6-membered rings with all aromatic bonds can be converted. This
    means we are getting things wrong for benzyne... but it's ok for now.

    Right now there aren't too many consequences for kinetics because there
    are very few 'Cb', 'Cbf' groups in the kinetic families. The reactions
    should still occur between the kekulized forms while the species uses
    aromatic thermo. However, now that we are storing an additional isomer
    this probably uses slightly more memory.

This looks like clear progress to me.