Wifi.status() always returns WL_NO_SHIELD
The problem is solved now. 


I imported the Adafruit_CC3000 library which can be downloaded here: https://github.com/adafruit/Adafruit_CC3000_Library
I run the example but the output was chinese nonsense
Instead of 

Serial.begin(115200);

I used 

Serial.begin(9600);

then the examples run without any problem


Thanks @Majenko. His question was very helpful.