Fix isSpeaking Signal for Mimic2 TTS (#1724)

Allows skills to determine while TTS is still occurring

mycroft/tts/mimic2_tts.py

@@ -17,7 +17,7 @@ from mycroft.tts import TTS, TTSValidator
 from mycroft.tts.remote_tts import RemoteTTS
 from mycroft.util.log import LOG
 from mycroft.util.format import pronounce_number
-from mycroft.util import play_wav, get_cache_directory
+from mycroft.util import play_wav, get_cache_directory, create_signal
 from requests_futures.sessions import FuturesSession
 from urllib import parse
 from .mimic_tts import VISIMES
@@ -258,6 +258,8 @@ class Mimic2(TTS):
             sentence (str): sentence to synthesize from mimic2
             ident (optional): Defaults to None.
         """
+        create_signal("isSpeaking")
+
         sentence = self._normalized_numbers(sentence)
         chunks = sentence_chunker(sentence, self.chunk_size)
         for idx, req in enumerate(self._requests(chunks)):