fix: packages/app/package.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JS-AXIOS-1038255

Author: snyk-bot

packages/app/package.json

@@ -92,7 +92,7 @@
     "apollo-link-batch-http": "^1.2.12",
     "apollo-link-context": "^1.0.18",
     "astring": "^1.4.3",
-    "axios": "^0.19.0",
+    "axios": "^0.21.1",
     "babel-code-frame": "^6.26.0",
     "babel-macros": "^2.0.0",
     "babel-plugin-jsx-pragmatic": "^1.0.2",