Changes to allow running in containers.

• Moved to the new executor and ensured it still runs directly.
• Fixed bugs in printing the summary output.

Fix for installation of Psi4

• Psi4 is now available on CondaForge, so install from there if requested.
• Psi4 crashes if asked to optimize and atom, so change to doing a single point energy is optimization is requested for and atom.

Enhancement of orbital plots

• Added structure to the orbital plots
• Fixed a bug if the default number of cores was not 'available'

Thermochemistry and orbital plotting

• Added a thermochemistry step to calculate the vibrational corrections to the energy, enthalpy, and free energy
• Added plotting to cube files for density and orbitals

Added control over SCF convergence

• Able to set convergence criteria.
• Options for damping. level shifting and second-order SCF
• Set default for number of steps for optimization to 6*nAtoms to make it more explicit.

More thoroughly check Psi4 for errors when running

Check and throw errors for various issues when running Psi4, including whenever it does not complete successfully according to the output.

Finally -- maybe -- killing OptKing

Merge pull request #18 from molssi-seamm/dev

Still trying to kill OptKing!

Completely removing OptKing for time being

OptKing is causing compatibility issues, and is not currently being used in the Python, so am temporarily removing it.

Temporarily removing OptKing dependency

It is not currently used but is causing problems with other dependencies.

Bug fixes and documentation revamp

• Corrected bugs, including if no dispersion term requested
• Added preliminary version of accelerated optimization using MOPAC for Hessians, etc. May not fully work at the moment.
• Updated documentation theme and structure to match new style.