chore: bump ts-jest from 26.4.1 to 26.4.2 (#94)

Author: dependabot[bot]

package-lock.json

@@ -112,7 +112,7 @@
     "rollup-plugin-typescript2": "^0.28.0",
     "rxjs": "6.6.3",
     "semantic-release": "17.2.1",
-    "ts-jest": "^26.4.1",
+    "ts-jest": "^26.4.2",
     "tslint": "^6.1.3",
     "tslint-config-prettier": "^1.18.0",
     "typedoc": "^0.19.2",