chore(deps): update dependency lerna to v3.21.0

Author: renovate-bot

package.json

@@ -45,7 +45,7 @@
     "eslint": "6.5.1",
     "husky": "3.0.8",
     "jest": "24.9.0",
-    "lerna": "3.17.0",
+    "lerna": "3.21.0",
     "prettier": "1.18.2",
     "puppeteer": "1.20.0",
     "webpack": "4.41.0",