chore(package): update ts-jest to version 26.1.0

Closes #59

Author: greenkeeper[bot]

package.json

@@ -34,7 +34,7 @@
     "prettier": "^1.16.0",
     "react": "^16.8.0-alpha.1",
     "react-test-renderer": "^16.8.0-alpha.1",
-    "ts-jest": "^24.0.2",
+    "ts-jest": "^26.1.0",
     "typescript": "^3.2.4"
   },
   "peerDependencies": {