updated packages for turf-clusters-dbscan

 - remove unused packages
 - add rbush

Author: TadaTeruki

packages/turf-clusters-dbscan/package.json

@@ -58,7 +58,6 @@
   "devDependencies": {
     "@turf/centroid": "^7.0.0-alpha.2",
     "@turf/clusters": "^7.0.0-alpha.2",
-    "@types/density-clustering": "^1.3.0",
     "@types/tape": "*",
     "benchmark": "*",
     "chromatism": "*",
@@ -75,7 +74,7 @@
     "@turf/distance": "^7.0.0-alpha.2",
     "@turf/helpers": "^7.0.0-alpha.2",
     "@turf/meta": "^7.0.0-alpha.2",
-    "density-clustering": "1.3.0",
+    "rbush": "^3.0.1",
     "tslib": "^2.3.0"
   }
 }