[FIX] Lookup raises in threaded environment. See note. (#688)

In threaded applications, if the user does not explictly create a new 
event loop then one does not exist.

twint/run.py

@@ -258,13 +258,37 @@ def Following(config):
 
 def Lookup(config):
     logme.debug(__name__+':Lookup')
+
+    try:
+        get_event_loop()
+    except RuntimeError as e:
+        if "no current event loop" in str(e):
+            set_event_loop(new_event_loop())
+        else:
+            logme.exception(__name__+':Lookup:Unexpected exception while handling an expected RuntimeError.')
+            raise
+    except Exception as e:
+        logme.exception(__name__+':Lookup:Unexpected exception occured while attempting to get or create a new event loop.')
+        raise
+
+    try:
         if config.User_id is not None:
             logme.debug(__name__+':Twint:Lookup:user_id')
             config.Username = get_event_loop().run_until_complete(get.Username(config.User_id))
+
         url = f"https://twitter.com/{config.Username}?lang=en"
         get_event_loop().run_until_complete(get.User(url, config, db.Conn(config.Database)))
+
         if config.Pandas_au:
             storage.panda._autoget("user")
+    except RuntimeError as e:
+        if "no current event loop" in str(e):
+            logme.exception(__name__+':Lookup:Previous attempt to to create an event loop failed.')
+
+        raise
+    except Exception as e:
+        logme.exception(__name__+':Lookup:Unexpected exception occured.')
+        raise
 
 def Profile(config):
     logme.debug(__name__+':Profile')