[es6-bookreader-core/Toolbar] create Toolbar.test.js
[es6-bookreader-core/Toolbar] create Toolbar.test.js

openlibrary/bookreader,openlibrary/bookreader,openlibrary/bookreader,openlibrary/bookreader,internetarchive/bookreader,internetarchive/bookreader,openlibrary/bookreader