Changed the default way to modify values in store. Added basic validation to stores. Using interfaces to DI store objects.

Requests/UpdateTTSVoice.cs

@@ -12,7 +12,7 @@ namespace HermesSocketServer.Requests
         private IStore<string, TTSVoice> _voices;
         private ILogger _logger;
 
-        public UpdateTTSVoice(VoiceStore voices, ILogger logger)
+        public UpdateTTSVoice(IStore<string, TTSVoice> voices, ILogger logger)
         {
             _voices = voices;
             _logger = logger;