Fix svn URLs on Windows

Resolves ESMCI/manage_externals#166

Author: billsacks

manic/repository_svn.py

@@ -44,9 +44,9 @@ def __init__(self, component_name, repo, ignore_ancestry=False):
         Repository.__init__(self, component_name, repo)
         self._ignore_ancestry = ignore_ancestry
         if self._branch:
-            self._url = os.path.join(self._url, self._branch)
+            self._url = self._url + '/' + self._branch
         elif self._tag:
-            self._url = os.path.join(self._url, self._tag)
+            self._url = self._url + '/' + self._tag
         else:
             msg = "DEV_ERROR in svn repository. Shouldn't be here!"
             fatal_error(msg)