chore: lock deps

Co-Authored-By: Emanuele <my.burning@gmail.com>

package.json

@@ -142,7 +142,7 @@
     "babel-preset-env": "1.7.0",
     "babel-preset-jest": "24.6.0",
     "codecov": "3.5.0",
-    "commitizen": "^4.0.3",
+    "commitizen": "4.0.3",
     "commitlint-config-cz": "0.12.0",
     "conventional-changelog-cli": "2.0.21",
     "cz-customizable": "6.2.0",