chore(package): update ts-jest to version 25.5.0

Closes #74

Author: greenkeeper[bot]

package.json

@@ -21,7 +21,7 @@
     "husky": "^4.0.2",
     "jest": "^23.6.0",
     "semantic-release": "^11.0.2",
-    "ts-jest": "^24.0.0",
+    "ts-jest": "^25.5.0",
     "tslint": "^5.11.0",
     "tslint-microsoft-contrib": "^5.2.1",
     "typescript": "^3.1.3",