updated mgxs library mesh test
updated mgxs library mesh test

johnnyliu27/openmc,johnnyliu27/openmc,walshjon/openmc,paulromano/openmc,shikhar413/openmc,shikhar413/openmc,liangjg/openmc,smharper/openmc,walshjon/openmc,mit-crpg/openmc,johnnyliu27/openmc,liangjg/openmc,paulromano/openmc,johnnyliu27/openmc,wbinventor/openmc,bhermanmit/openmc,smharper/openmc,mit-crpg/openmc,bhermanmit/openmc,smharper/openmc,liangjg/openmc,amandalund/openmc,smharper/openmc,shikhar413/openmc,paulromano/openmc,walshjon/openmc,liangjg/openmc,walshjon/openmc,paulromano/openmc,mit-crpg/openmc,amandalund/openmc,wbinventor/openmc,amandalund/openmc,amandalund/openmc,wbinventor/openmc,shikhar413/openmc,mit-crpg/openmc,wbinventor/openmc