Bump umi from 3.2.16 to 3.2.20 (#79)

Bumps [umi](https://github.com/umijs/umi) from 3.2.16 to 3.2.20.
- [Release notes](https://github.com/umijs/umi/releases)
- [Commits](umijs/umi@v3.2.16...v3.2.20)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

package.json

@@ -33,7 +33,7 @@
     "husky": "^4.2.5",
     "react-test-renderer": "^16.7.0",
     "typescript": "^4.0.2",
-    "umi": "^3.2.16"
+    "umi": "^3.2.20"
   },
   "husky": {
     "hooks": {