Bump typescript from 2.6.2 to 2.7.1

Bumps [typescript](https://github.com/Microsoft/TypeScript) from 2.6.2 to 2.7.1.
- [Release notes](https://github.com/Microsoft/TypeScript/releases)
- [Commits](microsoft/TypeScript@v2.6.2...v2.7.1)

Author: dependabot-support

package-lock.json

@@ -28,7 +28,7 @@
     "prettier": "1.10.2",
     "source-map-loader": "^0.2.3",
     "tape": "^4.8.0",
-    "typescript": "^2.6.2",
+    "typescript": "^2.7.1",
     "webpack": "^3.10.0",
     "webpack-node-externals": "^1.6.0"
   }