Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2235)

Add certifcate selection tests: the certificate type is selected by cipher
string and signature algorithm.
Reviewed-by: NEmilia Käsper <emilia@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2224)