Cryptography requirements change due to versioning

Hi team,

The cryptography package has updated its versioning approach, and due to this `pyjwt` installation fails with the following error:
```
error: cryptography 35.0.0 is installed but cryptography<4.0.0,>=3.3.1 is required by {'PyJWT'}
```
Would be great to change this requirement for PyJWT as well.