Update openmc/capi/plot.py
Update openmc/capi/plot.py

Co-Authored-By: Paul Romano <a436801bae4f27296736e9545e95ef593e23fd3e@gmail.com>
liangjg/openmc,smharper/openmc,liangjg/openmc,walshjon/openmc,liangjg/openmc,paulromano/openmc,amandalund/openmc,walshjon/openmc,walshjon/openmc,amandalund/openmc,mit-crpg/openmc,smharper/openmc,smharper/openmc,shikhar413/openmc,mit-crpg/openmc,paulromano/openmc,amandalund/openmc,liangjg/openmc,shikhar413/openmc,mit-crpg/openmc,walshjon/openmc,paulromano/openmc,mit-crpg/openmc,shikhar413/openmc,smharper/openmc,amandalund/openmc,shikhar413/openmc,paulromano/openmc