Fix issue with currentTime, secondsLoaded, and duration not loading

[alexshoe]

Component property fixes:

• Adding the following line helps to trigger currentTime, secondsLoaded, and duration to update:

componentDidMount() {
    this.updateDuration()
}

• Component was rebuilt and tested with all usage files, everything works as intended and expected.

---

Additional changes:

• Re-adding the @plotly scope to the package, but building the package without an "@plotly" directory
• Simplifies build command to npm run build
• Updates DESCRIPTION file
• Fixes description for className in source code

[alexcjohnson]

💃 LGTM!