It was only used by sso-server, which is not being built. This
package is not available in Debian buster.

The expiration timestamp was added to the current time upon
deserialization, as if it were an offset. Fix the ambiguity in the
internal API.

Refactor ticket deserialization code

See merge request !5

Drop Python 2 support

See merge request !4

For mod_sso tests.

Redirect the user to the (unauthenticated) destination, so that it
might try again the request. This introduces potential for a redirect
loop unfortunately, so let's see how well it works.

Matches a specific production config that needed to be tested.

Again another package required for hermetic testing.

Will run tests in the package build phase.

Prevents spurious dependencies in the other libraries.

Nonce

See merge request !3

Validation error details are also moved behind the 'debug' option,
in order to reduce noise.

The native Python module implements a narrower interface and is much
simpler than the SWIG-wrapped version (the Python sso module API stays
the same).

The native Python module supports Python 3.

First steps towards Python 3 compatibility.