Update dependency jest to v26

Author: renovate-bot

package.json

@@ -34,7 +34,7 @@
     "@types/jest": "22.2.3",
     "@types/redis": "2.8.6",
     "codecov": "3.0.1",
-    "jest": "23.0.0",
+    "jest": "26.1.0",
     "standard": "10.0.3",
     "ts-jest": "22.4.4",
     "tslint": "5.9.1",