fix: package.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-NODENOTIFIER-1035794

Author: snyk-bot

package.json

@@ -59,7 +59,7 @@
     "eslint-plugin-import": "^2.18.2",
     "eslint-plugin-jest": "^22.17.0",
     "husky": "^0.14.3",
-    "jest": "^24.9.0",
+    "jest": "^26.0.0",
     "jest-when": "^2.7.0",
     "prettier": "^1.13.7",
     "pretty-quick": "^1.6.0",