Feat/drand js support

[driemworks]

This closes #20, It adds support for Drand's quicknet to the timelock.js library.

• it adds support for curve configuration in the wasm-pack wrapper functions that we compile to js/wasm
• it adds support to configure the curve in javascript by specifying a curve identity
• it adds enhanced error handling to the ts wrapper
• it moves the example to a new directory

[juangirini]

LGTM
(just cleaned up some commented out code)