Merge branch 'release/1.1.2' into develop
added a header image, and fixed css
Modified font-size, 13px -> 16px.
Modified image url.
Modified Contents
Modified a stopwatch class. and Updated composer.json.
Added a test code of \Hnsta\StopWatch
Modified Readme.md
Refoemated code
Merge branch 'release/1.1.3'