message: MINOR: Removed usage of chai.assert
diff: import { OrientedBox3 } from "@here/harp-geometry";
  import { MathUtils, Projection, ProjectionType, TileKey, TilingScheme } from "@here/harp-geoutils";
  -import { assert } from "chai";
  +import { assert } from "@here/harp-utils";
  import * as THREE from "three";
  import { CalculationStatus, ElevationRangeSource } from "./ElevationRangeSource";
  import { MapTileCuller } from "./MapTileCuller";
  