(v1.2) Major update

Updates:

• Updated the way subscribing to a Websocket works:
  • Changed subscription from quote to instrument:
    • Updates state when the value chages, not every 1 second.
  • Subscribes to XBTUSD and ETHUSD at the same time on connect: (will consider adding more tickers later)
    • No more delay when switching tickers (now instant).
• Updated backend requests:
  • Removed CCXT dependency;
  • Requests are done with request module;
  • Custom error handling.
• Updated Websocket state handling: (price update is quite slow right now)
  • Most important parts of the message send through websocket are saved;
  • Improves scaling for later updates.
• Log messages done through custom logging to console;
• Added more error handling situations;
• Updated packages.

Fixes:

• Replaced public bootstrap version with a local one;
• Fixed tests;