Updated RELAX NG schema for hex_lattice
Updated RELAX NG schema for hex_lattice

johnnyliu27/openmc,smharper/openmc,bhermanmit/openmc,shikhar413/openmc,paulromano/openmc,shikhar413/openmc,paulromano/openmc,wbinventor/openmc,lilulu/openmc,amandalund/openmc,johnnyliu27/openmc,mjlong/openmc,samuelshaner/openmc,samuelshaner/openmc,smharper/openmc,kellyrowland/openmc,wbinventor/openmc,mit-crpg/openmc,johnnyliu27/openmc,amandalund/openmc,liangjg/openmc,paulromano/openmc,liangjg/openmc,walshjon/openmc,lilulu/openmc,bhermanmit/openmc,mit-crpg/openmc,walshjon/openmc,johnnyliu27/openmc,samuelshaner/openmc,mjlong/openmc,mit-crpg/openmc,amandalund/openmc,liangjg/openmc,wbinventor/openmc,samuelshaner/openmc,amandalund/openmc,walshjon/openmc,kellyrowland/openmc,shikhar413/openmc,wbinventor/openmc,mit-crpg/openmc,walshjon/openmc,lilulu/openmc,paulromano/openmc,liangjg/openmc,smharper/openmc,shikhar413/openmc,smharper/openmc