replace pymarketcap with coinmarketcap (#562)

* 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

freqtrade/tests/test_main.py

@@ -72,7 +72,6 @@ def test_main(mocker, caplog) -> None:
         ),
         clean=MagicMock(),
     )
-
     args = ['-c', 'config.json.example']
 
     # Test Main + the KeyboardInterrupt exception