Tests

1. [Create a window and set up the main scene.](https://github.com/Ethosa/nodesnim/blob/master/tests/test1.nim) 2. [Use Canvas node.](https://github.com/Ethosa/nodesnim/blob/master/tests/test2.nim) 3. [Window events handling.](https://github.com/Ethosa/nodesnim/blob/master/tests/test3.nim) 4. [Use ColorRect node.](https://github.com/Ethosa/nodesnim/blob/master/tests/test4.nim) 5. [Handle Control node events.](https://github.com/Ethosa/nodesnim/blob/master/tests/test5.nim) 6. [Anchor setting.](https://github.com/Ethosa/nodesnim/blob/master/tests/test6.nim) 7. [Change scenes.](https://github.com/Ethosa/nodesnim/blob/master/tests/test7.nim)