Log Message:
Update security/py-certifi to 2015.9.6.2.

pkgsrc changes:
 o Simplify MASTER_SITES.
 o Get rid of the EGG_NAME redefinition (seems no more needed).

Changes:
2015.09.06.2
 o Ship weak cert bundle.
2015.09.06.1
 o Provide old cert bundle.
 o Use secure roots by defaults.
2015.09.06
 o Update scripts to use mkcert.org.