Modify ECDH Test vector loader for KDF vectors

Also add tests for the new vectors

Signed-off-by: Simo Sorce <simo@redhat.com>
diff --git a/docs/development/test-vectors.rst b/docs/development/test-vectors.rst
index 41531f7..c40a662 100644
--- a/docs/development/test-vectors.rst
+++ b/docs/development/test-vectors.rst
@@ -22,7 +22,7 @@
 * RSA FIPS 186-2 and PKCS1 v1.5 vulnerability test vectors from `NIST CAVP`_.
 * FIPS 186-2 and FIPS 186-3 DSA test vectors from `NIST CAVP`_.
 * FIPS 186-2 and FIPS 186-3 ECDSA test vectors from `NIST CAVP`_.
-* DH and ECDH test vectors from `NIST CAVP`_.
+* DH and ECDH and ECDH+KDF(17.4) test vectors from `NIST CAVP`_.
 * Ed25519 test vectors from the `Ed25519 website_`.
 * OpenSSL PEM RSA serialization vectors from the `OpenSSL example key`_ and
   `GnuTLS key parsing tests`_.