include DHT-11 sensor

[UnaiFernandez]

The next step on the project is to include the DHT-11 sensor to measure the humidity and the temperature.

• [x] start signal
• [x] receive signal from DHT11
• [x] get data from DHT11
• [x] Send data via tcp to the client
• [x] Function to get data
• [x] Comment the code
• [x] Documentation