* Add OAuth2 redirect page for Swagger UI. This allows having delegated authentication in the Swagger UI docs. For this to work, you need to add `{your_origin}/docs/oauth2-redirect` to the allowed callbacks in your OAuth2 provider (in Auth0, Facebook, Google, etc).
    * For example, during development, it could be `http://localhost:8000/docs/oauth2-redirect`.

- golang.org/x/image: 0694c2d → cff245a
- golang.org/x/lint: 959b441 → fdd1cda
- golang.org/x/mobile: d3739f8 → d2bd2a2
- golang.org/x/mod: 4bf6d31 → v0.3.0
- golang.org/x/net: 13f9640 → ab34263
- golang.org/x/oauth2: 0f29369 → 858c2ad
- golang.org/x/sys: fde4db3 → ed371f2
- golang.org/x/text: v0.3.2 → v0.3.3
- golang.org/x/time: 9d24e82 → 555d28b
- golang.org/x/tools: 65e3620 → c1934b7
- golang.org/x/xerrors: a985d34 → 9bdfabe