Install arduino env for CI

.gitlab-ci.yml

@@ -1,3 +1,15 @@
+before_script:
+  - Xvfb :1 -nolisten tcp -screen :1 1280x800x24 &
+  - xvfb="$!"
+  - export DISPLAY=:1
+  - arduino --pref "boardsmanager.additional.urls=http://arduino.esp8266.com/stable/package_esp8266com_index.json" --save-prefs
+  - arduino --install-boards esp8266:esp8266
+  - arduino --board esp8266:esp8266:generic --save-prefs
+  - arduino --pref "compiler.warning_level=all" --save-prefs
+
+after_script:
+  - kill -9 $xvfb
+
 WifiControlSensor:
   script:
     - arduino --verify WifiControlSensor.ino