Revert KeyVault version to 3.0.4 (#4326)

- Version was accidentally incremented in a044362739 (diff-34ec7e8370f59c8b845594c62c3e960e)

lib/services/keyVault/package.json

@@ -2,7 +2,7 @@
   "name": "azure-keyvault",
   "author": "Microsoft Corporation",
   "description": "KeyVaultClient Library with typescript type definitions for node",
-  "version": "3.1.0",
+  "version": "3.0.4",
   "dependencies": {
     "ms-rest": "^2.3.2",
     "ms-rest-azure": "^2.5.5"