Added conditional to prevent exceeding of 500 characters limit of API

mastobot.py

@@ -104,6 +104,11 @@ for account in transitions:
         mastodon_text += "\n\nPosted " + parse(str(status.created_at)).strftime("%d. %B %Y - %H:%M on Twitter")
         mastodon_text += "\nOrigin: https://twitter.com/" + account['twitter_handle'] + "/status/" + tweet_origin
 
+		# Make sure that 500 char limit of Mastodon-API doesn't break the script                                                                               
+        if len(mastodon_text) > 500:
+        	mastodon_text = mastodon_text[:489]
+        
+        
         # Output text to stdout respect. post it to Mastodon.
         print(mastodon_text)