fix(deps): update dependency shelljs to v0.8.4

Author: renovate-bot

package.json

@@ -56,7 +56,7 @@
     "inquirer": "3.3.0",
     "lazy-ass": "1.6.0",
     "require-relative": "0.8.7",
-    "shelljs": "0.8.3",
+    "shelljs": "0.8.4",
     "simple-commit-message": "4.0.13",
     "validate-commit-msg": "2.14.0",
     "word-wrap": "1.2.3"