Upgrade to tuf 4.0 (or cap securesystemslib version)

[jku]

Hi,

I suggest updating your tuf dependency to 4.x:

• python-tuf did not cap the securesystemslib dependency before this release (sorry about that)
• we know there will be incompatible API changes in securesystemslib in future as we get closer to securesystemslib 1.0

So ideally python-tuf users make releases that require (or at least allow) tuf 4.x before securesystemslib makes their next release (secure-systems-lab/securesystemslib#767). If you don't want to bump tuf version you could alternatively cap securesystemslib to < 0.32 yourself: this would be the minimal change that should prevent future breakage.

[dennisvang]

@jku Thanks for the warning. I'll have a look at it a.s.a.p.

[dennisvang]

@jku Our latest v0.8.0 release now includes the upgraded tuf 4.0 dependency.

Sorry this took so long, I haven't had much time lately.