message: remove unused headers.
diff: #include <voxblox/core/common.h>
  #include <voxblox/mesh/mesh_layer.h>
  -/*#include <algorithm>
  -#include <eigen_conversions/eigen_msg.h>
  -#include <visualization_msgs/Marker.h>
  -
  -#include <voxblox/core/common.h>
  -#include <voxblox/integrator/esdf_integrator.h>
  -#include <voxblox/integrator/tsdf_integrator.h>
  -#include <voxblox/mesh/mesh.h>
  -#include <voxblox/mesh/mesh_layer.h>
  -
  -#include "voxblox_ros/conversions.h"*/
  -
  namespace voxblox {
  inline void toPCLPolygonMesh(const MeshLayer& mesh_layer,
  