Releasing 1.5.2

[kazu-yamamoto]

At least one project is suffering from the issue fixed by #394:
snoyberg/http-client#415

So, I would like to release v1.5.2 in a few days if there is no objections.

Cc: @snoyberg

[ocheron]

I think we should enable TLS13 and document in the changelog that supportedVersions has been reversed.

[kazu-yamamoto]

tls v1.5.2 and tls-debug v0.4.8 have been released.