Move part of game code to Game namespace

spec/queue_spec.cr

@@ -4,7 +4,7 @@ require "./../src/game/command"
 
 macro define_dummy_classes(count)
   {% for i in (1...count) %}
-    class Test::DummyCommand{{ i }} < Command
+    class Test::DummyCommand{{ i }} < Game::Command
       def start(world) : Int32
       end
 

spec/world_spec.cr

@@ -3,18 +3,18 @@ require "../src/game/world"
 
 describe "World" do
   it "should build crystal harvester" do
-    world = World.new
+    world = Game::World.new
     point = Point.new(2, 3)
-    cmd = BuildCrystalHarvesterCommand.new(point)
+    cmd = Game::BuildCrystalHarvesterCommand.new(point)
     world.push(cmd)
     world.run(100)
     world.map.get(point).has_role(TileRole::CrystalHarvester)
   end
 
   it "should fail when not enought resources" do
-    world = World.new
+    world = Game::World.new
     point = Point.new(2, 3)
-    cmd = BuildCrystalRestorerCommand.new(point)
+    cmd = Game::BuildCrystalRestorerCommand.new(point)
     expect_raises(NotEnoughtResources) do
       world.push(cmd)
     end