Refactor EventHandler, InvokEventHandler and ProcEventHandler tests
Tests: Refactor the main module test
Small fix: `TreeNode#name` is `Widget#name` indeed
Merge pull request #115 from kuraga/refactor-event_handler_test

Refactor EventHandler, InvokEventHandler and ProcEventHandler tests
Merge pull request #116 from kuraga/patch-5

Small fix: `TreeNode#name` is `Widget#name` indeed
Merge pull request #110 from kuraga/refactor-apotomo_test

Refactor the main module test