`cryptography` and `pyOpenSSL` installed by `pip install meltano` are incompatible
As can be seen in https://gitlab.com/meltano/meltano/-/jobs/883954260:
```
Collecting cryptography==2.9.2 (from meltano==1.59.0)
Downloading https://files.pythonhosted.org/packages/58/95/f1282ca55649b60afcf617e1e2ca384a2a3e7a5cf91f724cf83c8fbe76a1/cryptography-2.9.2-cp35-abi3-manylinux1_x86_64.whl (2.7MB)
<snip>
Collecting pyOpenSSL<21.0.0,>=16.2.0 (from snowflake-connector-python<3.0.0->snowflake-sqlalchemy==1.2.3->meltano==1.59.0)
Downloading https://files.pythonhosted.org/packages/c9/86/e21398551956735fef8f7883908771445878ccb16cd17c0896176419cd75/pyOpenSSL-20.0.0-py2.py3-none-any.whl (54kB)
<snip>
pkg_resources.ContextualVersionConflict: (cryptography 2.9.2 (/builds/meltano/meltano/meltano-projects/.venv/lib/python3.6/site-packages), Requirement.parse('cryptography>=3.2'), {'pyOpenSSL'})
```
`requirements.txt` requires `cryptography==2.9.2` as of https://gitlab.com/meltano/meltano/-/merge_requests/1884, which was compatible with `pyOpenSSL` 19.1.0 which got installed previously (https://gitlab.com/meltano/meltano/-/jobs/870504798), but not with the newly released 20.0.0 (https://pypi.org/project/pyOpenSSL/), which states `The minimum cryptography version is now 3.2.`
We should make Meltano depend on compatible versions again.
issue