Bump ts-jest from 25.3.1 to 25.4.0 (#79)

Bumps [ts-jest](https://github.com/kulshekhar/ts-jest) from 25.3.1 to 25.4.0.
- [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/v25.3.1...v25.4.0)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

package.json

@@ -38,7 +38,7 @@
     "jest-circus": "^25.4.0",
     "jest-runtime": "^25.4.0",
     "prettier": "^2.0.4",
-    "ts-jest": "^25.3.1",
+    "ts-jest": "^25.4.0",
     "typescript": "^3.8.3",
     "typescript-formatter": "^7.2.2"
   }