Correct timestamp format
This makes two changes to the timestamp format used in assertions.
- It removes the millisecond component, per issue #23, and
- It removes the timezone component, which is explicitly disallowed by the SAML spec (section 1.3.3)
I originally started working on this pull request because I believed my IDP (SimpleSAMLphp) did not tolerate timezones in timestamps, but it turns out that SimpleSAMLphp is actually slightly spec non-compliant itself and requires timestamps to be formatted as having a literal Z at the end.
For now I'm going to use a fork of flask-saml2 to prop up my IDP, and PR the upstream, although this lends credence to @ianlintner-wf's suggestion of making datetimes customizable
Please let me know if you suggest any other changes.
It seems like the checks are failing on an unrelated dependency issue, but please let me know if this is something in my code
I was recently informed that the Z at the end of the timestamp is mandatory, and I've added it to the timestamp