Move pairing check to the relevant stt backends

The pairing trigger should only be triggered by the 401 status for the
Mycroft hosted STT backends. Doing it for other STT's is only confusing.

This creates the decorator 'requires_pairing' that can be applied to the STT modules where it's relevant.

This adds the decorator to the MycroftSTT and the MycroftDeepSpeechSTT

mycroft/client/speech/listener.py

@@ -16,7 +16,7 @@ import time
 from threading import Thread
 import speech_recognition as sr
 from pyee import EventEmitter
-from requests import RequestException, HTTPError
+from requests import RequestException
 from requests.exceptions import ConnectionError
 
 from mycroft import dialog
@@ -215,12 +215,6 @@ class AudioConsumer(Thread):
             LOG.error("Connection Error: {0}".format(e))
 
             self.emitter.emit("recognizer_loop:no_internet")
-        except HTTPError as e:
-            if e.response.status_code == 401:
-                LOG.warning("Access Denied at mycroft.ai")
-                return "pair my device"  # phrase to start the pairing process
-            else:
-                LOG.error(e.__class__.__name__ + ': ' + str(e))
         except RequestException as e:
             LOG.error(e.__class__.__name__ + ': ' + str(e))
         except Exception as e:

mycroft/stt/__init__.py

@@ -20,7 +20,7 @@ from speech_recognition import Recognizer
 from queue import Queue
 from threading import Thread
 
-from mycroft.api import STTApi
+from mycroft.api import STTApi, HTTPError
 from mycroft.configuration import Configuration
 from mycroft.util.log import LOG
 
@@ -118,11 +118,33 @@ class IBMSTT(BasicSTT):
                                              self.password, self.lang)
 
 
+def requires_pairing(func):
+    """Decorator kicking of pairing sequence if client is not allowed access.
+
+    Checks the http status of the response if an HTTP error is recieved. If
+    a 401 status is detected returns "pair my device" to trigger the pairing
+    skill.
+    """
+    def wrapper(*args, **kwargs):
+        try:
+            return func(*args, **kwargs)
+        except HTTPError as e:
+            if e.response.status_code == 401:
+                LOG.warning('Access Denied at mycroft.ai')
+                # phrase to start the pairing process
+                return 'pair my device'
+            else:
+                raise
+    return wrapper
+
+
 class MycroftSTT(STT):
+    """Default mycroft STT."""
     def __init__(self):
         super(MycroftSTT, self).__init__()
         self.api = STTApi("stt")
 
+    @requires_pairing
     def execute(self, audio, language=None):
         self.lang = language or self.lang
         try:
@@ -138,6 +160,7 @@ class MycroftDeepSpeechSTT(STT):
         super(MycroftDeepSpeechSTT, self).__init__()
         self.api = STTApi("deepspeech")
 
+    @requires_pairing
     def execute(self, audio, language=None):
         language = language or self.lang
         if not language.startswith("en"):