Append a forward slash to the base_url

six.moves.urllib.parse.urljoin strips everything that doesn't end
with a forward slash, so for example, if the barbican URL is
http://ip-address/key-manager, the "key-manager" part will be removed.
If the URL is http://ip-address/key-manager/, everything will be fine.

Change-Id: I1afcd7ae460633e451bc365fdb87f6e30bb3a60b

castellan/key_manager/barbican_key_manager.py

@@ -202,8 +202,12 @@ class BarbicanKeyManager(key_manager.KeyManager):
             latest_version = raw_data[-1]
             api_version = latest_version.get('id')
 
+        if endpoint[-1] != '/':
+            endpoint += '/'
+
         base_url = urllib.parse.urljoin(
             endpoint, api_version)
+
         return base_url
 
     def create_key(self, context, algorithm, length,

castellan/tests/unit/key_manager/test_barbican_key_manager.py

@@ -76,6 +76,24 @@ class BarbicanKeyManagerTestCase(test_key_manager.KeyManagerTestCase):
         self.key_mgr._barbican_client = self.mock_barbican
         self.key_mgr._current_context = self.ctxt
 
+    def test_base_url_old_version(self):
+        version = "v1"
+        self.key_mgr.conf.barbican.barbican_api_version = version
+        endpoint = "http://localhost:9311"
+        base_url = self.key_mgr._create_base_url(mock.Mock(),
+                                                 mock.Mock(),
+                                                 endpoint)
+        self.assertEqual(endpoint + "/" + version, base_url)
+
+    def test_base_url_new_version(self):
+        version = "v1"
+        self.key_mgr.conf.barbican.barbican_api_version = version
+        endpoint = "http://localhost/key_manager"
+        base_url = self.key_mgr._create_base_url(mock.Mock(),
+                                                 mock.Mock(),
+                                                 endpoint)
+        self.assertEqual(endpoint + "/" + version, base_url)
+
     def test_create_key(self):
         # Create order_ref_url and assign return value
         order_ref_url = ("http://localhost:9311/v1/orders/"