ECDH curves exercised are OpenPGP recommended set: ANSIx9p{256,384,521}r1
and BRAINPOOLp{256,384,512}r1, plus X25519 and ED25519.
Signature is only tested (for now ?) with ED25519 as other signature schemes
are (usually) non-deterministic and require implementing the signature
verification algorithm rather than just testing for equality with a test
vector.
Signed-off-by: Vincent Pelletier <plr.vincent@gmail.com>