Change Bytes to ByteString

[erikd]

Bytes was a type alias for ByteString. The Bytes type is kept
because it is exposed in the API.

Have built http-client-tls and warp-tls from Hackage with this
version of tls and zero changes were needed in those packages.

Related to #229 . I have no problem whatsoever moving from Bytes/ByteString to ByteArray but while Bytes and ByteString are the same, Bytes should be replaced with ByteString if it can be done without breaking the API (and it can).

[erikd]

The build failures are when building the tasty package. See UnkindPartition/tasty#166

[erikd]

Ping?

[ocheron]

There is still the question to deprecate or simply remove the type alias.
Since we couldn't decide, the safe way would be to deprecate in this PR.

[erikd]

The code in this PR will not cause any difficulty at all in client code. No compile errors, no warnings, no changes in behavior. I would therefore advise against deprecating the Bytes type until there is a more major change is required.

[erikd]

Since what is on master already has breaking changes, I'd be happy to remove the Bytes type all together or at the very least deprecating it.

[kazu-yamamoto]

We should ping @vincenthz.

[ocheron]

I think we can't be wrong deprecating the type alias (and possibly moving the definition to Network.TLS itself). If it's used out of tls, it's probably by accident.

[erikd]

@ocheron I added a commit to do as you suggested.

[kazu-yamamoto]

Though @vincenthz does not respond, I would like to merge this PR.