chore(package): update ts-jest to version 24.0.0

Closes #8

Author: greenkeeper[bot]

package.json

@@ -27,7 +27,7 @@
     "joi": "12",
     "rimraf": "^2.6.2",
     "standard-version": "^4.4.0",
-    "ts-jest": "^22.4.6",
+    "ts-jest": "^24.0.0",
     "typescript": "^2.9.1"
   },
   "peerDependencies": {