Fix 500 exception when sending a non-string release name to appr

Fixes https://jira.coreos.com/browse/QS-120

endpoints/appr/test/test_registry.py

@@ -1,3 +1,4 @@
+import base64
 import json
 
 from flask import url_for
@@ -37,3 +38,27 @@ def test_login(login_data, expected_code, app, client):
 
   rv = client.open(url, method='POST', data=json.dumps(data), headers=headers)
   assert rv.status_code == expected_code
+
+
+@pytest.mark.parametrize('release_name', [
+  '1.0',
+  '1',
+  1,
+])
+def test_invalid_release_name(release_name, app, client):
+  params = {
+    'namespace': 'devtable',
+    'package_name': 'someapprepo',
+  }
+
+  url = url_for('appr.push', **params)
+  auth = base64.b64encode('devtable:password')
+  headers = {'Content-Type': 'application/json', 'Authorization': 'Basic ' + auth}
+  data = {
+    'release': release_name,
+    'media_type': 'application/vnd.cnr.manifest.v1+json',
+    'blob': 'H4sIAFQwWVoAA+3PMQrCQBAF0Bxlb+Bk143nETGIIEoSC29vMMFOu3TvNb/5DH/Ot8f02jWbiohDremT3ZKR90uuUlty7nKJNmqKtkQuTarbzlo8x+k4zFOu4+lyH4afvbnW93/urH98EwAAAAAAAAAAADb0BsdwExIAKAAA',
+  }
+
+  rv = client.open(url, method='POST', data=json.dumps(data), headers=headers)
+  assert rv.status_code == 422