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

Closes #60

Author: greenkeeper[bot]

package.json

@@ -69,7 +69,7 @@
     "style-loader": "^1.0.0",
     "stylelint": "^11.1.1",
     "stylelint-config-recommended": "^3.0.0",
-    "ts-jest": "^24.1.0",
+    "ts-jest": "^25.4.0",
     "ts-node-dev": "^1.0.0-pre.44",
     "tslint": "^5.20.1",
     "tslint-config-prettier": "^1.18.0",