Adopted .travis.xml from image-builder-rpi
Adopted .travis.xml from image-builder-rpi

docbobo/image-builder-odroid-c2,docbobo/image-builder-odroid-c2,midnightconman/image-builder-odroid-c2,gdeverlant/image-builder-odroid-c2,hypriot/image-builder-odroid-c2,gdeverlant/image-builder-odroid-c2,midnightconman/image-builder-odroid-c2,hypriot/image-builder-odroid-c2