chore(package): update ts-jest to version 25.4.0

Closes #53

Author: greenkeeper[bot]

package.json

@@ -50,7 +50,7 @@
     "lint-staged": "^9.1.0",
     "prettier": "^1.18.2",
     "semantic-release": "^15.13.18",
-    "ts-jest": "^24.0.2",
+    "ts-jest": "^25.4.0",
     "tslint": "^5.18.0",
     "typescript": "^3.5.2",
     "validate-commit-msg": "^2.12.1"