Merge branch 'mtnord-master-patch-94129' into 'master'

.gitlab-ci.yml

pom.xml

src/main/java/fi/utu/tech/Main.java

src/main/resources/application.css

src/main/resources/images/barrier1.png

src/main/resources/images/barrier2.png

src/main/resources/images/barrier3.png

src/main/resources/images/barrier4.png

src/main/resources/images/barrier5.png

src/main/resources/images/barrier6.png

src/main/resources/images/bullet.png

src/main/resources/images/explosion.png

src/main/resources/images/gameover.png

src/main/resources/images/invader1.png

src/main/resources/images/invader2.png

src/main/resources/images/invader3.png

src/main/resources/images/life.png

src/main/resources/images/player.png

src/main/resources/soundeffects/.gitkeep

src/main/resources/soundeffects/explosion.wav