Squashed 'deps/Catch/' content from commit 785db43

git-subtree-dir: deps/Catch
git-subtree-split: 785db43bb2cd64bfe795ba1c6adef8b82b85430d
Merge commit '140d5f85847b22ee13a01ea20d1d3a2675d51bb3' as 'deps/Catch'
Added event utility class and unit test