* prepare to support FIAT/Crypto trading
* Don't fail fiat-convert for unsupported stake currencies
* remove commented code
* Add BNB to cryptomap
* Fix test-failure
* related to random execution as fee was not properly mocked if this is
one of the first tests
* replace pymarketcap with coinmarketcap
* fix tests to use coinmarketcap instead of pymarketcap
* use arraypos 0
* update setup.py from pymarketcap to coinmarketcap
* Add test to check for unsupported Crypto currency
Result in a speed up of the unittest from 60s to 4s
Because it cost time to load Pymarketcap() every time we create
a CryptoToFiatConverter, it worth it to change it into a
Singleton.
