v2.1.3 Goodbye TravisCI, hello successful builds with GitHub Actions

Working, but otherwise using old library versions, Python 2.7 release

Maintenance release, does two big things:

1. Pins versions so this successfully builds. It's still Python 2.7, but at least it builds and the tests pass. Massive thanks to @spoeschel for this!
2. Switches the CI from TravisCI to GitHub Actions so we have our CI back.

Full Changelog: v2.1.2...v2.1.3

What's next?

I really don't plan on another Python 2.x release. Next up will be Python 3.7+

Final Python2 release.

This release fixes a number of bugs in v2.1.1 and is intended to be the last Python2 release we publish. Future releases will be based on Python 3.7+.

Fixes in this release:

• #474 the User Input Producer served via GitHub pages now displays live messages (for handover etc) correctly.
• #477 no longer specify pytest-capturelog (it is not needed anymore)
• #490 fix the way some fixtures are called, to track changes in pytest
• #496 restrict autobahn version to pre-18 as a temporary fix for the way that autobahn tests work
• #507 interpret decimal fractions of seconds correctly when they are not 3 digits long
• #502 when the Resequencer issues an empty document, do not always use sequence number 1
• #505 the Resequencer can begin emitting documents before it has received any
• #447 the Resequencer now has documentation
• #492 when a timing type is specified in an element, do not crash
• #514 issue better error messages for ERR_DOCUMENT_NOT_COMPATIBLE

Deduplicator and more

This minor point release fixes a bunch of small things that were a bit annoying, adds a style and region deduplicator, and simplifies the file system carriage mechanism, removing the "simple" option that really wasn't!

• Adds DeDuplicator node
• Fixes a build destination problem
• Removes filesystem-simple carriage mechanism, moving its functionality into filesystem
• Filter out badly timed elements as per the spec
• Include non-maintenance comment in direct scripts (in favour of ebu-run)
• Fix hyperlink dependency issue (temporary fix hopefully)
• Change documentation build destination and URLs in documentation so they don't use backwards relative links
• Provide a pre-built User Input Producer web page
• Fix XSD to allow foreign namespace content as per spec
• Add line numbers to computed line BDD tests so that failures can be located
• Fix documentation home page slack sign-up link to be an email request, since the linked page no longer works.

Specification conformance release

This release offers full conformance with the EBU Tech3370 v1 and Tech3370s1 v1 specifications, we think!

New functionality includes:

• Handover Manager Node
• A better funkier User Input Producer web page
• Retiming Delay Node adds an appliedProcessing element to demonstrate metadata use
• Better documentation

Bugs fixed:

• The rejection of multiple input sequences by nodes that can't handle them.
• ttm:agent XSD definition.

Release 2.0.1

Minor point update with fixes to test.html, moved into the ui folder.