Move constants to setup.py (#10312)

* Remove unused import

* Move setup relevant consts to 'setup.py'

* remove blank line

* Set source

homeassistant/components/dialogflow.py

@@ -9,7 +9,7 @@ import logging
 
 import voluptuous as vol
 
-from homeassistant.const import PROJECT_NAME, HTTP_BAD_REQUEST
+from homeassistant.const import HTTP_BAD_REQUEST
 from homeassistant.helpers import intent, template
 from homeassistant.components.http import HomeAssistantView
 
@@ -26,6 +26,8 @@ DOMAIN = 'dialogflow'
 
 INTENTS_API_ENDPOINT = '/api/dialogflow'
 
+SOURCE = "Home Assistant Dialogflow"
+
 CONFIG_SCHEMA = vol.Schema({
     DOMAIN: {}
 }, extra=vol.ALLOW_EXTRA)
@@ -128,5 +130,5 @@ class DialogflowResponse(object):
         return {
             'speech': self.speech,
             'displayText': self.speech,
-            'source': PROJECT_NAME,
+            'source': SOURCE,
         }