Inconsistent cryptography version in dependencies

[mvanbaak]

The version for the cryptography dependency was pinned in 81fe921 to force a version that does not depend on rust during build-time.
But, in the version number in requirements.txt is not the same as the one in setup.py

• setup.py states version <=3.3.2
• requirements.txt states version ==3.4.2

Which one should it be?

Note: This is a build-time only dependency, and on most platforms users should use the whl packages provided by cryptography. So, dropping the version number is, in my humble opinion, the way froward