Add TheThingsNetwork as library to install

Author: johanstokking

.travis.yml

@@ -11,7 +11,7 @@ before_install:
   - sudo ln -s /usr/local/share/arduino/arduino /usr/local/bin/arduino
 install:
   - ln -s $PWD /usr/local/share/arduino/libraries/TheThingsNode
-  - arduino --install-library "DHT sensor library:1.3.0,Adafruit Unified Sensor:1.0.2"
+  - arduino --install-library "DHT sensor library:1.3.0,Adafruit Unified Sensor:1.0.2,TheThingsNetwork:2.3.1"
   - git clone https://github.com/sparkfun/arduino_boards /tmp/sparkfun
   - mv /tmp/sparkfun/sparkfun /usr/local/share/arduino/hardware/sparkfun
 before_script: