Add copy of existing show_flux.py
Add copy of existing show_flux.py

paulromano/openmc,shikhar413/openmc,paulromano/openmc,amandalund/openmc,paulromano/openmc,amandalund/openmc,liangjg/openmc,walshjon/openmc,liangjg/openmc,shikhar413/openmc,mit-crpg/openmc,mit-crpg/openmc,amandalund/openmc,liangjg/openmc,shikhar413/openmc,amandalund/openmc,walshjon/openmc,liangjg/openmc,shikhar413/openmc,mit-crpg/openmc,mit-crpg/openmc,paulromano/openmc,walshjon/openmc,walshjon/openmc