Remove dependent module py3kcompat

Sync commit of removing py3kcompat from oslo

Change-Id: Icb7740a3652c26f0c1da3688aae7fb5b10b5c3e2
Closes-Bug: #1280033
Log the command output on CertificateConfigError

In auth_token middleware if the CertificateConfigError is raise for a reason
other than the certificate file missing or the ca cert file missing, log the
actual output from the verify comment to aid in correcting the issue.

Related-Bug: #1285833
Change-Id: I6b469b9037b7ef59993132f87a75152149ee6310
Merge "Log the command output on CertificateConfigError"
Merge "Remove dependent module py3kcompat"