Update ts-jest to the latest version 🚀 (#28)

* chore(package): update ts-jest to version 25.1.0

* chore(package): update lockfile package-lock.json

Author: greenkeeper[bot]

package-lock.json

@@ -36,7 +36,7 @@
     "jest": "^23.6.0",
     "prettier": "^1.15.3",
     "semantic-release": "^17.0.0",
-    "ts-jest": "^24.0.0",
+    "ts-jest": "^25.1.0",
     "ts-node": "^8.0.3",
     "tslint": "^5.12.1",
     "tslint-config-prettier": "^1.17.0",