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

Closes #162

Author: greenkeeper[bot]

package.json

@@ -79,7 +79,7 @@
     "rollup-plugin-commonjs": "^9.0.0",
     "rollup-plugin-node-resolve": "^5.0.0",
     "semantic-release": "^15.9.16",
-    "ts-jest": "^23.10.4",
+    "ts-jest": "^25.4.0",
     "ts-node": "^7.0.0",
     "tslint": "^5.2.0",
     "tslint-config-standard": "^8.0.0",