clean up x509 tests & add DSA/ECDSA tests
clean up x509 tests & add DSA/ECDSA tests

bwhmather/cryptography,bwhmather/cryptography,skeuomorf/cryptography,bwhmather/cryptography,Ayrx/cryptography,Ayrx/cryptography,Hasimir/cryptography,skeuomorf/cryptography,sholsapp/cryptography,Hasimir/cryptography,skeuomorf/cryptography,sholsapp/cryptography,kimvais/cryptography,kimvais/cryptography,Ayrx/cryptography,sholsapp/cryptography,Hasimir/cryptography,sholsapp/cryptography,Hasimir/cryptography,kimvais/cryptography,Ayrx/cryptography,bwhmather/cryptography,kimvais/cryptography,skeuomorf/cryptography