Rebase on master

Author: MathiasKoch

src/config.rs

@@ -4,7 +4,7 @@ use crate::cipher_suites::CipherSuite;
 use crate::extensions::extension_data::signature_algorithms::SignatureScheme;
 use crate::extensions::extension_data::supported_groups::NamedGroup;
 use crate::handshake::certificate::CertificateRef;
-use crate::handshake::certificate_verify::CertificateVerifyRef;
+pub use crate::handshake::certificate_verify::CertificateVerifyRef;
 use crate::TlsError;
 use aes_gcm::{AeadInPlace, Aes128Gcm, Aes256Gcm, KeyInit};
 use digest::core_api::BlockSizeUser;