treat roles_path as the list it is for galaxy list

lib/ansible/cli/galaxy.py

@@ -485,12 +485,13 @@ class GalaxyCLI(CLI):
         else:
             # show all valid roles in the roles_path directory
             roles_path = self.get_opt('roles_path')
-            roles_path = os.path.expanduser(roles_path)
-            if not os.path.exists(roles_path):
+            for path in roles_path:
+                role_path = os.path.expanduser(path)
+                if not os.path.exists(role_path):
                     raise AnsibleOptionsError("- the path %s does not exist. Please specify a valid path with --roles-path" % roles_path)
-            elif not os.path.isdir(roles_path):
+                elif not os.path.isdir(role_path):
                     raise AnsibleOptionsError("- %s exists, but it is not a directory. Please specify a valid path with --roles-path" % roles_path)
-            path_files = os.listdir(roles_path)
+                path_files = os.listdir(role_path)
                 for path_file in path_files:
                     gr = GalaxyRole(self.galaxy, path_file)
                     if gr.metadata: