fix(package): update rimraf to version 3.0.1

Closes #68

Author: greenkeeper[bot]

package.json

@@ -69,7 +69,7 @@
     "mkdirp": "^0.5.1",
     "node-fetch": "^2.6.0",
     "openpgp": "^4.5.5",
-    "rimraf": "^2.6.3",
+    "rimraf": "^3.0.1",
     "which": "^1.3.1"
   },
   "devDependencies": {