New

• Popover: close with [esc]
• Tooltip: remove title attribute, closes #183

Fixed

• Transform arrow functions into class methods (#152)
• prevent popovers from staying open when moving mouse too quickly (#228)
• Popover: hide when deactivated
• Popover: use div instead of span, closes #123
• Tooltip: bind show and hide methods, fix _hide is not a function
• Tooltip: properly remove aria-describedby when tooltip is removed from DOM, closes #191