Merge branch '10-add-a-numbers-skin' into 'master'

android/gradle.properties

assets/icons/skin_numbers.png

assets/skins/numbers_0.png

assets/skins/numbers_1.png

assets/skins/numbers_2.png

assets/skins/numbers_3.png

assets/skins/numbers_4.png

assets/skins/numbers_5.png

assets/skins/numbers_6.png

assets/skins/numbers_7.png

assets/skins/numbers_8.png

icons/build_game_icons.sh

icons/skin_numbers.svg

icons/skins/numbers/0.svg

icons/skins/numbers/1.svg

icons/skins/numbers/2.svg

icons/skins/numbers/3.svg

icons/skins/numbers/4.svg

icons/skins/numbers/5.svg

icons/skins/numbers/6.svg