Fix bing recognition, add Amazon Lex (though not documented yet, README fixes)

Author: Uberi

README.rst

@@ -254,7 +254,7 @@ The "bt_audio_service_open" error means that you have a Bluetooth audio device,
 
 For errors of the form "ALSA lib [...] Unknown PCM", see `this StackOverflow answer <http://stackoverflow.com/questions/7088672/pyaudio-working-but-spits-out-error-messages-each-time>`__. Basically, to get rid of an error of the form "Unknown PCM cards.pcm.rear", simply comment out ``pcm.rear cards.pcm.rear`` in ``/usr/share/alsa/alsa.conf``, ``~/.asoundrc``, and ``/etc/asound.conf``.
 
-For "jack server is not running or cannot be started" or "connect(2) call to /dev/shm/jack-1000/default/jack_0 failed (err=No such file or directory)" or "attempt to connect to server failed", these are caused by ALSA trying to connect to JACK, and can be safely ignored. I'm not aware of any simple way to turn those messages off at this time, besides [entirely disabling printing while starting the microphone](https://github.com/Uberi/speech_recognition/issues/182#issuecomment-266256337).
+For "jack server is not running or cannot be started" or "connect(2) call to /dev/shm/jack-1000/default/jack_0 failed (err=No such file or directory)" or "attempt to connect to server failed", these are caused by ALSA trying to connect to JACK, and can be safely ignored. I'm not aware of any simple way to turn those messages off at this time, besides `entirely disabling printing while starting the microphone <https://github.com/Uberi/speech_recognition/issues/182#issuecomment-266256337>`__.
 
 On OS X, I get a ``ChildProcessError`` saying that it couldn't find the system FLAC converter, even though it's installed.
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make-release.sh

@@ -8,5 +8,5 @@ set -o pipefail # for a pipeline, if any of the commands fail with a non-zero ex
 echo "Making release for SpeechRecognition-$1"
 
 python setup.py bdist_wheel
-gpg2 --detach-sign -a dist/SpeechRecognition-$1-*.whl
+gpg --detach-sign -a dist/SpeechRecognition-$1-*.whl
 twine upload dist/SpeechRecognition-$1-*.whl dist/SpeechRecognition-$1-*.whl.asc

speech_recognition/__init__.py

@@ -1108,6 +1108,40 @@ def recognize_bing(self, audio_data, key, language="en-US", show_all=False):
         if "RecognitionStatus" not in result or result["RecognitionStatus"] != "Success" or "DisplayText" not in result: raise UnknownValueError()
         return result["DisplayText"]
 
+    def recognize_lex(self, audio_data, bot_name, bot_alias, user_id, content_type="audio/l16; rate=16000; channels=1", access_key_id=None, secret_access_key=None, region=None):
+        """
+        Performs speech recognition on ``audio_data`` (an ``AudioData`` instance), using the Amazon Lex API.
+
+        If access_key_id or secret_access_key is not set it will go through the list in the link below
+        http://boto3.readthedocs.io/en/latest/guide/configuration.html#configuring-credentials
+        """
+        assert isinstance(audio_data, AudioData), "Data must be audio data"
+        assert isinstance(bot_name, str), "``bot_name`` must be a string"
+        assert isinstance(bot_alias, str), "``bot_alias`` must be a string"
+        assert isinstance(user_id, str), "``user_id`` must be a string"
+        assert isinstance(content_type, str), "``content_type`` must be a string"
+        assert access_key_id is None or isinstance(access_key_id, str), "``access_key_id`` must be a string"
+        assert secret_access_key is None or isinstance(secret_access_key, str), "``secret_access_key`` must be a string"
+        assert region is None or isinstance(region, str), "``region`` must be a string"
+
+        try:
+            import boto3
+        except ImportError:
+            raise RequestError("missing boto3 module: ensure that boto3 is set up correctly.")
+
+        client = boto3.client('lex-runtime', aws_access_key_id=access_key_id,
+                              aws_secret_access_key=secret_access_key,
+                              region_name=region)
+
+        raw_data = audio_data.get_raw_data(
+            convert_rate=16000, convert_width=2
+        )
+
+        accept = "text/plain; charset=utf-8"
+        response = client.post_content(botName=bot_name, botAlias=bot_alias, userId=user_id, contentType=content_type, accept=accept, inputStream=raw_data)
+
+        return response["inputTranscript"]
+
     def recognize_houndify(self, audio_data, client_id, client_key, show_all=False):
         """
         Performs speech recognition on ``audio_data`` (an ``AudioData`` instance), using the Houndify API.