Added total charge and multiplicity to input

Merge pull request #13 from molssi-seamm/dev

Added total charge and spin multiplicity to the input.

Added property handling

Merge pull request #12 from molssi-seamm/dev

Added property handling

Updated for changes in Psi4

Also cleaned up release and CI to use shared workflows.

Updating to Python 3.8 and 3.9

2021.10.13

Moving up to Python 3.8 and 3.9

Update for internal change in argument parsing.

2021.6.3

Updated for the seamm argument parser moving to seamm_util.

Added plug-in specific installer for Psi4

Added a plug-in specific installer that installs Psi4, by default in the seamm-psi4 conda environment.

Added to the documentation

Streamlined the documentation, adding a description for the plug-in.
Also tidied up the description for PyPI, which is used by the new installer, and added keywords to help with searches.

Updated for compatibility with the new system classes.

Merge pull request #9 from molssi-seamm/system2

Updated for compatibility with the new system classes.

Internal: moving to GitHub Actions for CI/CD

No change in functionality, but making sure that everything works using GitHub Action for continuous integration (CI) and deployment (CD)

Moving to new command-line argument handling

Merge pull request #7 from molssi-seamm/option-handling

Updating for the command-line argument handling