use yarn and updated dependencies

package.json

@@ -9,8 +9,8 @@
   "author": "Philippe Auriach",
   "license": "MIT",
   "dependencies": {
-    "@mapbox/sphericalmercator": "^1.0.5",
-    "geojson-vt": "^2.4.0",
-    "vt-pbf": "^3.0.1"
+    "@mapbox/sphericalmercator": "1.1.0",
+    "geojson-vt": "3.1.4",
+    "vt-pbf": "3.1.1"
   }
 }

yarn.lock

@@ -0,0 +1,50 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
+"@mapbox/[email protected]", "@mapbox/point-geometry@~0.1.0":
+  version "0.1.0"
+  resolved "https://registry.yarnpkg.com/@mapbox/point-geometry/-/point-geometry-0.1.0.tgz#8a83f9335c7860effa2eeeca254332aa0aeed8f2"
+
+"@mapbox/[email protected]":
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/@mapbox/sphericalmercator/-/sphericalmercator-1.1.0.tgz#f3b1af042620716a1289fc41e1e97f610823aefe"
+
+"@mapbox/vector-tile@^1.3.1":
+  version "1.3.1"
+  resolved "https://registry.yarnpkg.com/@mapbox/vector-tile/-/vector-tile-1.3.1.tgz#d3a74c90402d06e89ec66de49ec817ff53409666"
+  dependencies:
+    "@mapbox/point-geometry" "~0.1.0"
+
+[email protected]:
+  version "3.1.4"
+  resolved "https://registry.yarnpkg.com/geojson-vt/-/geojson-vt-3.1.4.tgz#c8ffefbe3613d3ad2747e963b0b63b9e62ff11b8"
+
+ieee754@^1.1.6:
+  version "1.1.12"
+  resolved "https://registry.yarnpkg.com/ieee754/-/ieee754-1.1.12.tgz#50bf24e5b9c8bb98af4964c941cdb0918da7b60b"
+
+pbf@^3.0.5:
+  version "3.1.0"
+  resolved "https://registry.yarnpkg.com/pbf/-/pbf-3.1.0.tgz#f70004badcb281761eabb1e76c92f179f08189e9"
+  dependencies:
+    ieee754 "^1.1.6"
+    resolve-protobuf-schema "^2.0.0"
+
+protocol-buffers-schema@^2.0.2:
+  version "2.2.0"
+  resolved "https://registry.yarnpkg.com/protocol-buffers-schema/-/protocol-buffers-schema-2.2.0.tgz#d29c6cd73fb655978fb6989691180db844119f61"
+
+resolve-protobuf-schema@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/resolve-protobuf-schema/-/resolve-protobuf-schema-2.0.0.tgz#e67b062a67f02d11bd6886e70efda788407e0fb4"
+  dependencies:
+    protocol-buffers-schema "^2.0.2"
+
+[email protected]:
+  version "3.1.1"
+  resolved "https://registry.yarnpkg.com/vt-pbf/-/vt-pbf-3.1.1.tgz#b0f627e39a10ce91d943b898ed2363d21899fb82"
+  dependencies:
+    "@mapbox/point-geometry" "0.1.0"
+    "@mapbox/vector-tile" "^1.3.1"
+    pbf "^3.0.5"