build(deps-dev): update typescript requirement from ^2.7.2 to ^3.1.1

Updates the requirements on [typescript](https://github.com/Microsoft/TypeScript) to permit the latest version.
- [Release notes](https://github.com/Microsoft/TypeScript/releases)
- [Commits](https://github.com/Microsoft/TypeScript/commits/v3.1.1)

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

package.json

@@ -160,7 +160,7 @@
     "ts-node": "^3.3.0",
     "tslint": "^5.8.0",
     "tslint-config-prettier": "^1.15.0",
-    "typescript": "^2.7.2",
+    "typescript": "^3.1.1",
     "webpack": "^3.5.5"
   }
 }