kafka callback in cryptostore collector wrongly labels kwargs 'bootstrap' as 'host'

[qinghuangchan]

Describe the bug
A clear and concise description of what the bug is.

In cryptostore/collector.py line 77
kwargs = {'host': self.config['kafka']['ip'], 'port': self.config['kafka']['port']}

However, in cryptofeed/backends/kafka.py, the KafkaCallback expects
def __init__(self, bootstrap='127.0.0.1', port=9092, key=None, numeric_type=float, **kwargs):

Cryptofeed Version
Master

[Bryant Moscon]

this has been fixed