v1.0.0-alpha.21

changes

• add support for drawer layout with display: flex
• add .mdk-drawer-layout--flex class (enables flexbox on the drawer layout)
• refactor header scroll transforms
• refactor reveal
• refactor scroll effects to use requestAnimationFrame instead of scroll events (performance)
• update demos
• upgrade laravel-mix to v2.0.0
• configure babel to use transform-runtime via .babelrc (fixes ie11 issues)