fixing async sample code (#412)

speech/api/README.md

@@ -72,6 +72,14 @@ for more information.
 
     You should see a response with the transcription result.
 
+* To run the `speech_async_rest.py` sample:
+
+    ```sh
+    $ python speech_async_rest.py resources/audio.raw
+    ```
+
+    You should see a response with the transcription result.
+
 * To run the `speech_streaming.py` sample:
 
     ```sh

speech/api/speech_async_rest.py

@@ -22,24 +22,23 @@
 import time
 
 from googleapiclient import discovery
+import httplib2
 from oauth2client.client import GoogleCredentials
 # [END import_libraries]
 
 
 # [START authenticating]
-DISCOVERY_URL = ('https://{api}.googleapis.com/$discovery/rest?'
-                 'version={apiVersion}')
 
 
 # Application default credentials provided by env variable
 # GOOGLE_APPLICATION_CREDENTIALS
 def get_speech_service():
     credentials = GoogleCredentials.get_application_default().create_scoped(
         ['https://www.googleapis.com/auth/cloud-platform'])
+    http = httplib2.Http()
+    credentials.authorize(http)
 
-    return discovery.build(
-        'speech', 'v1beta1', credentials=credentials,
-        discoveryServiceUrl=DISCOVERY_URL)
+    return discovery.build('speech', 'v1beta1', http=http)
 # [END authenticating]