Dash-daq

Fixed
- Fixed ThemeProvider warning by updating `styled-components` to `v4.4.0`.

Fixed
- Fixed "Cannot read property 'subscribe' of undefined" JavaScript
error.

Added
- Added `height` and `width` parameters to `daq.Tank` and
`daq.Thermometer`.

Changed
- Updated library to React 16 for compatibility with `dash-1.0.0`.

Added
- Added ability for LEDDisplay to handle negative numbers.

Fixed
- Fixed missing locationSlider entry in Slider.propTypes.

Added

- Updated package.json with additional metadata for R package
building.
- Added JavaScript bundle and source map to dash_daq subfolder.
- Initial commit of dashDaq R package.