chore(package): update @types/yargs to version 15.0.3

Closes #126

Author: greenkeeper[bot]

package.json

@@ -42,7 +42,7 @@
     "@types/glob": "^7.1.1",
     "@types/mocha": "^5",
     "@types/node": "~12.0.0",
-    "@types/yargs": "^13.0.0",
+    "@types/yargs": "^15.0.3",
     "chai": "^4",
     "conventional-changelog-cli": "^2.0.21",
     "conventional-commits-detector": "^1.0.2",