Calculate species rather than molecule's symmetry number.

Since we store aromatic forms as resonance isomer we need to pick the largest
symmetry number.
Add a requirements.txt for installing packages necessary for installing the website locally.
Modify code now that training reactions are defined in terms of species not molecule objects.
Fix bug in displaying structures by making getStructureInfo() more adaptable.
bugfix: import KineticsEntryEditForm and ThermoEntryEditForm so pages don't fail.