Xtcryptosignals

Added sparkline chart for each pair.
Added Team and Donations sections in `README.md` file.
Added Contact Form.
Code fixes.

Added changes and improvements in UI.
General Code fixes.

Added exchange:

* Binance DEX

Updated README.md.
Code refactoring and code fixes.

Added collection of data for any configured crypto-currency (coin or token) in
the following exchanges:

* Bitmax
* DCoin
* Bilaxy

Added Mongo data migrations capability.
All tickers will always be updated each 10 seconds compared with
referenced history ticker.
Added pairs LTO/BTC, LTO/ETH and LTO/USDT in `settings_exchanges.py`.
Setup and added testing to the whole framework.
General Code fixes.

Added support for dev and prod (using eventlet and Gunicorn) environments when
running `xt-server` and `xt-client`.
Added real-time active number of users in dashboard page.
Added 6 more Tickers.
Added adequate mongodb collection indexes to improve data fetching performance.

Code improvements related with project configuration.