INSTALL.txt: Remove old references to pre-py3 packages

[apjanke]

Fixes #31.
Following up on #40 (comment).

INSTALL.txt has references to a bunch of prepackaged AsciiDoc distributions, left over from before the py3 port.

This PR removes the old references.

This PR keeps the Fedora Linux reference, since that one appears to be updated to use asciidoc-py3 as of Rawhide (based on my Googling and manually examining http://fedora.portingdb.xyz/pkg/asciidoc/ and https://rpmfind.net/linux/RPM/fedora/devel/rawhide/s390x/a/asciidoc-8.6.10-0.7.20180605git986f99d.fc29.noarch.html). From their changelog:

* Tue Jun 05 2018 Josef Ridky <jridky@redhat.com> - 8.6.8-16.986f99d
  - New upstream version with Python3 support - asciidoc-py3 (commit 986f99d)

I checked the links for the rest of them, and they're either using the old Python2 AsciiDoc or dead links.

[elextr]

Thanks very much, I made #31 but hadn't found time to do it yet.

Sorry to nitpick, but are the people listed on fedora still correct?

@aerostitch you wouldn't happen to know of any other distro packages of this coming up, hint hint? 😉

[apjanke]

You're welcome.

Sorry to nitpick, but are the people listed on fedora still correct?

No idea, and I wouldn't know how to verify that at this point.

Maybe the names should just be removed, since the package is maintained by the Fedora project as a whole, and not individual contributors?

[elextr]

Maybe the names should just be removed, since the package is maintained by the Fedora project as a whole, and not individual contributors?

Sounds like the best solution yeah.

[apjanke]

Done.

[elextr]

I think I fixed the conflicts with #40 correctly, never tried it with the online editor before.

[aerostitch]

@aerostitch you wouldn't happen to know of any other distro packages of this coming up, hint hint? wink

@elextr I'm planning on upgrading the asciidoc package to the asciidoc-py3 package soon in Debian 😄
I'm mostly waiting to get my key updated in hte Debian keyring which should happen in the next 10 days.
I got a few changes queued up after that and asciidoc changes is part of this TODO queue 😉

Tho I'd really appreciate a tagged release on the repo to avoid having to do weird version numbering hacks... 😜

[MasterOdin]

It may make sense to make a 8.6.10 release in this repo at cc9b6c8 to match asciidoc-py2's 8.6.10 release at 37f6baa and then cut a new 8.7.0 release to signify the new python version, as this repo was created and split and then some commits happened in the py2 repo. Or do 8.7.0-beta# or something.

[aerostitch]

I think that changing the runtime would be a reason to do a major release if we follow semantic versioning as we drop the backward compatibility with python 2. So 9.0.0?