Add test for uvloop fix

tests/exchange/test_exchange.py

@@ -18,21 +18,13 @@ from freqtrade.exchange.exchange import (market_is_active, timeframe_to_minutes,
                                          timeframe_to_next_date, timeframe_to_prev_date,
                                          timeframe_to_seconds)
 from freqtrade.resolvers.exchange_resolver import ExchangeResolver
-from tests.conftest import get_patched_exchange, log_has, log_has_re
+from tests.conftest import get_mock_coro, get_patched_exchange, log_has, log_has_re
 
 
 # Make sure to always keep one exchange here which is NOT subclassed!!
 EXCHANGES = ['bittrex', 'binance', 'kraken', 'ftx']
 
 
-# Source: https://stackoverflow.com/questions/29881236/how-to-mock-asyncio-coroutines
-def get_mock_coro(return_value):
-    async def mock_coro(*args, **kwargs):
-        return return_value
-
-    return Mock(wraps=mock_coro)
-
-
 def ccxt_exceptionhandlers(mocker, default_conf, api_mock, exchange_name,
                            fun, mock_ccxt_fun, retries=API_RETRY_COUNT + 1, **kwargs):