None of our regression tests use RMS reactors

[rwest]

The testing framework runs the examples in RMG-Py/test/regression
which use the following reactor types:

aromatics/input.py:simpleReactor(
liquid_oxidation/input.py:liquidReactor(
nitrogen/input.py:simpleReactor(
oxidation/input.py:simpleReactor(
sulfur/input.py:simpleReactor(
sulfur/input.py:simpleReactor(
superminimal/input.py:simpleReactor(

so the RMS reactor types are not being tested in this CI framework.

I think at least one of the regression tests should use an RMS reactor, so that a "full run" of RMG that uses RMS is tested via CI.

[JacksonBurns]

So we have an example from @mjohnson541 that uses the RMS Constant V Ideal Gas Reactor here already on hand - all we need is a regression_input.py (like we have for the other examples used in regression testing) and it could easily be added. I don't know how do this myself, though.