Factory method for make (fanci) script

[kzsigmond]

What changed

Created a factory method for wfn_type in make_script and make_fanci_script. Added option for custom wave function type.

Why

Previously one had to edit the output of make_script if the wave function was not in make_script.

How

make_script gets a method for a given wfn_type from get_wfn_info. These wfn_type dependent methods return the import_line, wfn_name, and wfn_kwargs, which make_scripts uses later. The custom wave function method looks for wfn_name and import_from in wfn_kwargs. For example, wfn_kwarg for the CISD wave function would be wfn_kwargs = "wfn_name = CISD, import_from = fanpy.wfn.ci.cisd"

Testing

• comparison of old wfn information and information from factory
• test to see if the from import line still works
• test for raising ValueError for incorrect wfn_type
• used the write_wfn_py method of run_calc to generate calculate.py for custom and cisd wfn_type