switch to react and remove moment

[TheLartians]

As discussed in #28:

• Switch from jQuery to React
• Remove the moment package in favour of the JS's built-in Date class
• Update the readme to reflect the changes

Also implicitly undos the change from #29 to avoid including dead code. Webpack should already resolve any imported files from the entry points.

[chibat]

@TheLartians Thank you for your PR ! I would like to reconsider about #26, #29 .