Added Arduino 1.6.9 to the continuous integration

.travis.yml

@@ -107,6 +107,7 @@ matrix:
     - env: SCRIPT=arduino VERSION=1.5.8 BOARD=arduino:avr:uno
     - env: SCRIPT=arduino VERSION=1.6.7 BOARD=arduino:avr:uno
     - env: SCRIPT=arduino VERSION=1.6.8 BOARD=arduino:avr:uno
+    - env: SCRIPT=arduino VERSION=1.6.9 BOARD=arduino:avr:uno
     - env: SCRIPT=platformio BOARD=uno
     - env: SCRIPT=platformio BOARD=due
     - env: SCRIPT=platformio BOARD=esp01