ssh provider has limit to sshtunnel  < 0.2
https://github.com/apache/airflow/blob/9d6ae609b60449bd274c2f96e72486d73ad2b8f9/setup.py#L451

I don't know why? sshtunnel  already released 0.4
I didn't open PR because I don't know this provider i just tried to install it and couldn't due to conflicts with other requirements in my system so eventually i used vitrual env to solve my problem but logging this issue so that someone who knows this code can handle it.
setup.py
'tableauserverclient',
]
samba = [
    'smbprotocol>=1.5.0',
]
segment = [
    'analytics-python>=1.2.9',
]
sendgrid = [
    'sendgrid>=6.0.0,<7',
]
sentry = [
    'blinker>=1.1',
    'sentry-sdk>=0.8.0',
]
singularity = ['spython>=0.0.56']
slack = [
    'slack_sdk>=3.0.0,<4.0.0',
]
snowflake = [
    'snowflake-connector-python>=2.4.1',
    'snowflake-sqlalchemy>=1.1.0',
]
spark = [
    'pyspark',
]
ssh = [
    'paramiko>=2.6.0',
    'pysftp>=0.2.9',
    'sshtunnel>=0.1.4,<0.2',