chore(package): update ts-jest to version 23.10.5

Closes #13

Author: greenkeeper[bot]

package.json

@@ -118,7 +118,7 @@
     "rxjs": "^5.5.6",
     "rxjs-marbles": "^2.3.1",
     "semantic-release": "^15.0.0",
-    "ts-jest": "^22.0.0",
+    "ts-jest": "^23.10.5",
     "ts-node": "^5.0.1",
     "tslint": "^5.8.0",
     "tslint-config-prettier": "^1.1.0",