Adds Oauth support to plugins

packages/medusa-plugin-discount-generator/package.json

@@ -14,6 +14,7 @@
     "@babel/core": "^7.7.5",
     "@babel/node": "^7.7.4",
     "@babel/plugin-proposal-class-properties": "^7.7.4",
+    "@babel/plugin-transform-classes": "^7.9.5",
     "@babel/plugin-transform-instanceof": "^7.8.3",
     "@babel/plugin-transform-runtime": "^7.7.6",
     "@babel/preset-env": "^7.7.5",