Update dependency @turf/helpers to v6.3.0

Author: renovate-bot

package.json

@@ -35,7 +35,7 @@
     ]
   },
   "dependencies": {
-    "@turf/helpers": "6.1.4",
+    "@turf/helpers": "6.3.0",
     "es6-promise": "4.2.5",
     "mapbox-gl": "0.49.0",
     "unfetch": "3.1.1"

yarn.lock

@@ -687,9 +687,10 @@
   dependencies:
     any-observable "^0.3.0"
 
-"@turf/helpers@6.1.4":
-  version "6.1.4"
-  resolved "https://registry.yarnpkg.com/@turf/helpers/-/helpers-6.1.4.tgz#d6fd7ebe6782dd9c87dca5559bda5c48ae4c3836"
+"@turf/helpers@6.3.0":
+  version "6.3.0"
+  resolved "https://registry.yarnpkg.com/@turf/helpers/-/helpers-6.3.0.tgz#87f90f806c3f8ad6385ef8d2041d3662bf3c9fb1"
+  integrity sha512-kr6KuD4Z0GZ30tblTEvi90rvvVNlKieXuMC8CTzE/rVQb0/f/Cb29zCXxTD7giQTEQY/P2nRW23wEqqyNHulCg==
 
 "@webassemblyjs/ast@1.5.13":
   version "1.5.13"