added "Hello World" example in Scala language
added "Hello World" example in Scala language

florianbussmann/hello-world,florianbussmann/hello-world,florianbussmann/hello-world,florianbussmann/hello-world,florianbussmann/hello-world,florianbussmann/hello-world,florianbussmann/hello-world,florianbussmann/hello-world,florianbussmann/hello-world,florianbussmann/hello-world,florianbussmann/hello-world,florianbussmann/hello-world