Tag more document versions

[hsiaoyi0504]

It seems to me that the document hosted on read the docs: https://readthedocs.org/projects/django-pipeline/ doesn't have newer versions since 1.6.9, but we are 1.6.14 now.

@cyberdelia can you either add new versions for this or add me to the maintainers on the read the docs ?

[cyberdelia]

I enabled the missing ones by hand, hopefully we can get something automated here: jazzband/help#99

[jpmckinney]

Noting that the docs on ReadTheDocs are out-of-date, e.g. I can't read about Terser at https://django-pipeline.readthedocs.io/en/latest/compressors.html though it's at https://github.com/jazzband/django-pipeline/blob/master/docs/compressors.rst

[bckohan]

Still broken.