Release 1.3.1

A quick follow up release to 1.3.0 to fix a bug that has plagued GSS NTLMSSP for a long time and deserves to be released asap

What's Changed

• Make sending only filled MsvAvFlags field for CHALLENGE message by @FeoOne in #98
• Release version 1.3.1 by @simo5 in #101

New Contributors

• @FeoOne made their first contribution in #98

Full Changelog: v1.3.0...v1.3.1