deps: bump @zeit/ncc from 0.20.5 to 0.21.0

Bumps [@zeit/ncc](https://github.com/zeit/ncc) from 0.20.5 to 0.21.0.
- [Release notes](https://github.com/zeit/ncc/releases)
- [Commits](https://github.com/zeit/ncc/compare/0.20.5...0.21.0)

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

package.json

@@ -56,7 +56,7 @@
     "@types/jest": "^24.0.24",
     "@types/node": "^12.12.21",
     "@typescript-eslint/parser": "^2.12.0",
-    "@zeit/ncc": "^0.20.5",
+    "@zeit/ncc": "^0.21.0",
     "eslint": "^6.8.0",
     "husky": "^3.1.0",
     "jest": "^24.9.0",