Bump @types/node from 12.7.12 to 15.6.1

Bumps [@types/node](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/node) from 12.7.12 to 15.6.1.
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/node)

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -27,7 +27,7 @@
   "homepage": "https://github.com/geostyler/geostyler-shapefile-parser#readme",
   "dependencies": {
     "@types/jest": "^24.0.18",
-    "@types/node": "^12.7.12",
+    "@types/node": "^15.6.1",
     "@types/shpjs": "^3.4.0",
     "geostyler-data": "^1.0.0",
     "geostyler-geojson-parser": "^1.0.1",