backblaze - hyper dependencies are out of date

[thinkrapido]

Hi,

I want to upgrade the hyper dependencies as well to the latest state.
This means hyper 0.10 -> 014.

Unfortunately, this is not possible because the very old backblaze-b2 crate is out of date (5 years).
And this one uses hyper 0.10.

It might be an alternative to talk to the backblaze-b2 guys and ask, if they would likely republish the hyper depencencies in their crate.
This would make the dependency call for hyper and hyper-native-tls in the rdedup crate obsolete.

We would also write backend-b2 = ["backblaze-b2"] instead of backend-b2 = ["backblaze-b2", "hyper", "hyper-native-tls"] for the features.

See also:
#100

[dpc]

Seems fine to me.