chore(deps): update dependency ts-jest to v26.5.6

Author: renovate[bot]

package-lock.json

@@ -40,7 +40,7 @@
     "prettier": "2.0.5",
     "regenerator-runtime": "0.14.1",
     "semantic-release": "19.0.3",
-    "ts-jest": "26.5.1",
+    "ts-jest": "26.5.6",
     "tslint": "5.20.1",
     "tslint-config-prettier": "1.18.0",
     "tslint-plugin-prettier": "2.3.0",