Bump to 8.5.0

- Fixes email validation for public keys
- Fixes incorrect failed validation of contacts with missing user agents
- Adds validation to credit model
- Changes `min_billed_requirement` to `min_spent_requirement` on referral model that was recently added
- Adds count to referral model
- Patch to update referral sent count

package.json

@@ -1,6 +1,6 @@
 {
   "name": "storj-service-storage-models",
-  "version": "8.4.2",
+  "version": "8.5.0",
   "description": "common storage models for various storj services",
   "main": "index.js",
   "directories": {