Delete the func of build_app_v0()

The func of def build_app_v0 is not used any more.
Delete it.

Change-Id: I1d26cfc2f398cbf219adf59e2582096cb0600e73

freezer_api/cmd/api.py

@@ -66,29 +66,6 @@ def configure_app(app, db=None):
     return app
 
 
-# def build_app_v0():
-#     """Instantiate the root freezer-api app
-
-#  Old versions of falcon (< 0.2.0) don't have a named 'middleware' argument.
-#  This was introduced in version 0.2.0b1, so before that we need to instead
-#  provide "before" hooks (request processing) and "after" hooks (response
-#  processing).
-
-#     :return: falcon WSGI app
-#     """
-
-#     # injecting FreezerContext & hooks
-#     before_hooks = utils.before_hooks() + [
-#         middleware.RequireJSON().as_before_hook()]
-#     after_hooks = [middleware.JSONTranslator().as_after_hook()]
-#   # The signature of falcon.API() differs between versions, suppress pylint:
-#   # pylint: disable=unexpected-keyword-arg
-#     app = falcon.API(before=before_hooks, after=after_hooks)
-
-#     app = configure_app(app)
-#     return app
-
-
 def build_app_v1():
     """Building routes and forming the root freezer-api app