Removed core_map utility.
Removed core_map utility.

johnnyliu27/openmc,johnnyliu27/openmc,mjlong/openmc,smharper/openmc,wbinventor/openmc,wbinventor/openmc,liangjg/openmc,keadyk/openmc_mg_prepush,johnnyliu27/openmc,walshjon/openmc,keadyk/openmc_mg_prepush,mit-crpg/openmc,amandalund/openmc,samuelshaner/openmc,walshjon/openmc,lilulu/openmc,paulromano/openmc,smharper/openmc,wbinventor/openmc,sxds/opemmc,lilulu/openmc,sxds/opemmc,shikhar413/openmc,amandalund/openmc,shenqicang/openmc,bhermanmit/cdash,lilulu/openmc,kellyrowland/openmc,bhermanmit/openmc,mit-crpg/openmc,bhermanmit/openmc,samuelshaner/openmc,samuelshaner/openmc,mit-crpg/openmc,johnnyliu27/openmc,walshjon/openmc,keadyk/openmc_mg_prepush,nhorelik/openmc,liangjg/openmc,paulromano/openmc,smharper/openmc,samuelshaner/openmc,amandalund/openmc,shikhar413/openmc,smharper/openmc,mit-crpg/openmc,shikhar413/openmc,shenqicang/openmc,liangjg/openmc,paulromano/openmc,amandalund/openmc,paulromano/openmc,wbinventor/openmc,mjlong/openmc,kellyrowland/openmc,shikhar413/openmc,nhorelik/openmc,liangjg/openmc,walshjon/openmc