Optionally include extra certificate in package signature
Optionally include extra certificate in package signature

Ability to add extra cert to the PKCS7 signature, to support
Apple WWDR Intermediate Certificate renewal, per
https://developer.apple.com/support/certificates/expiration/

Pass path to AppleWWDRCA.cer file in extra_certificate parameter.
Old intermediate cert expires 02/14/16; new one expires 02/07/23
per https://www.apple.com/certificateauthority/

SymmetricInfinity/push_package