Fixes to various issues reported by pyflakes

Pyflake is a python (2) source checker. This patch fixes various
(mostly trivial) errors and warnings it reports.

Change-Id: Ia35c5ac61751b927814cf693994c632c412386ea

rest-api-templates/asterisk_processor.py

@@ -20,6 +20,7 @@
 Asterisk RESTful HTTP binding code.
 """
 
+import os
 import re
 
 from swagger_model import *

rest-api-templates/swagger_model.py

@@ -737,7 +737,7 @@ class ResourceListing(Stringify):
         self.swagger_version = resources_json.get('swaggerVersion')
         if not self.swagger_version in SWAGGER_VERSIONS:
             raise SwaggerError(
-                "Unsupported Swagger version %s" % swagger_version, context)
+                "Unsupported Swagger version %s" % self.swagger_version, context)
 
         validate_required_fields(resources_json, self.required_fields, context)
         self.api_version = resources_json['apiVersion']

rest-api-templates/transform.py

@@ -52,7 +52,6 @@ class Transform(object):
         dest_exists = os.path.exists(dest_file)
         if dest_exists and not self.overwrite:
             return
-        tmp_file = tempfile.mkstemp()
         with tempfile.NamedTemporaryFile() as out:
             out.write(renderer.render(self.template, model))
             out.flush()