Certificates were originally added in c000cb6471,
but did not include a script to generate them. Current versions of Go expect
certificates to use SAN instead of Common Name fields, so updating the script
to include those;
x509: certificate relies on legacy Common Name field, use SANs or temporarily
enable Common Name matching with GODEBUG=x509ignoreCN=0
Some fields were updated to be a bit more descriptive (instead of "replaceme"),
and the `-text` option was used to include a human-readable variant of the
content.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
