message: slam's default IndexType, PositionType and ElementType are now based on axom::IndexType
diff: #ifndef SLAM_UTILITIES_H_
  #define SLAM_UTILITIES_H_
  +#include "axom/core.hpp"
  +
  #include <string>
  namespace axom
  @@ -17,9 +19,9 @@ namespace axom
  namespace slam
  {
  -using IndexType = int;
  -using PositionType = int;
  -using ElementType = int;
  +using IndexType = axom::IndexType;
  +using PositionType = axom::IndexType;
  +using ElementType = axom::IndexType;
  class NotImplementedException
  {};
  