Bump ts-jest from 25.1.0 to 25.2.0 (#20)

Bumps [ts-jest](https://github.com/kulshekhar/ts-jest) from 25.1.0 to 25.2.0.
- [Release notes](https://github.com/kulshekhar/ts-jest/releases)
- [Changelog](https://github.com/kulshekhar/ts-jest/blob/master/CHANGELOG.md)
- [Commits](https://github.com/kulshekhar/ts-jest/compare/v25.1.0...v25.2.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

package.json

@@ -36,7 +36,7 @@
     "jest-circus": "^25.1.0",
     "jest-runtime": "^25.1.0",
     "prettier": "^1.17.1",
-    "ts-jest": "^25.1.0",
+    "ts-jest": "^25.2.0",
     "typescript": "^3.5.1",
     "typescript-formatter": "^7.2.2"
   }