fix(package): update which to version 2.0.1

Closes #73

Author: greenkeeper[bot]

package.json

@@ -70,7 +70,7 @@
     "node-fetch": "^2.6.0",
     "openpgp": "^4.5.5",
     "rimraf": "^2.6.3",
-    "which": "^1.3.1"
+    "which": "^2.0.1"
   },
   "devDependencies": {
     "eslint": "^6.0.1",