Remove CipherSuite (#20)

* Remove `Hash`

* Remove `CipherSuite`

* Remove single field `struct`s

src/ciphersuite.rs

@@ -1,17 +0,0 @@
-// Copyright (c) Facebook, Inc. and its affiliates.
-//
-// This source code is licensed under both the MIT license found in the
-// LICENSE-MIT file in the root directory of this source tree and the Apache
-// License, Version 2.0 found in the LICENSE-APACHE file in the root directory
-// of this source tree.
-
-//! Defines the CipherSuite trait to specify the underlying primitives for VOPRF
-
-/// Configures the underlying primitives used in VOPRF
-pub trait CipherSuite {
-    /// A finite cyclic group along with a point representation that allows some
-    /// customization on how to hash an input to a curve point. See `group::Group`.
-    type Group: crate::group::Group;
-    /// The main hash function to use (for HKDF computations and hashing transcripts).
-    type Hash: crate::hash::Hash;
-}