This fixes errors like:

    File "python3.6/lib/python3.6/re.py", line 142, in <module>
      class RegexFlag(enum.IntFlag):
  AttributeError: module 'enum' has no attribute 'IntFlag

It no longer exist at this URL

This version is python 3 compatible

extra_requires was added in slapos.core, which simplifies this part.

Because we run egg tests with setup.py test, which installs missing
eggs, if an egg was not installed by buildout, then it installed before
running test. This was the case for mock, which is now python3 only (
https://pypi.org/project/mock/4.0.0b1/ ) and we started to see test
failures.

To solve this issue, refactor the setup definition to use
extra_requires, which seems to work fine in buildout now. Keep
test_requires because it's the what `python setup.py test` uses.

Clean buildout profiles to install slapos.cookbook[test] for test
instead of duplicating the content of test_requires.

/reviewed-on nexedi/slapos!690

/reviewed-on nexedi/slapos!627

For now we just use a directory inside the partition as shared parts,
but we could also maybe one day also inject the shared_part_list from
this slapos.

This recipe already use all options defined in buildout for substitution
in the erp5testnode.cfg.in

slap_connection is a deprecated alias, we use kebab case in buildout
profiles.

/reviewed-on nexedi/slapos!688

This requires the "prerm" plugin be enabled to be used in addition to devperm. 

I tested on production and it works fine.

/cc @tomo

/reviewed-on nexedi/slapos!687

If there is IPv6 on both interface, Linux will put a default route on
ens3 preventing IPv6 to work correctly on ens4.
Even disabling totally IPv6 from inside the host on ens3 may not work.
It is safer to disable it from qemu process directly. Also, it will ease
the configuration of the host.

NBD server is not running until an image is uploaded. Make sure that the
promise doesn't fail until the image is there. Also display a WARNING in
the connection parameter to say that the NBD server is not running.

Recent fixes for proftpd were still not correct, we still have issues with rpath for mod_auth_web and proftpd itself which uses libcap if available, error was:
    
    ======================================================================
    ERROR: setUpModule (test)
    ----------------------------------------------------------------------
    Traceback (most recent call last):
      File "/srv/slappart11/cqg/soft/1ae6b62cded47f49a2e77af2f372cf2a/parts/slapos.core-repository/slapos/testing/testcase.py", line 154, in setUpModule
        installSoftwareUrlList(cls, [software_url], debug=debug)
      File "/srv/slappart11/cqg/soft/1ae6b62cded47f49a2e77af2f372cf2a/parts/slapos.core-repository/slapos/testing/testcase.py", line 348, in installSoftwareUrlList
        raise e
    RuntimeError: /srv/slappart11/cqg/inst/test0-0/tmp/soft/728168be59c5353c6e3c6a6bc4cad052/parts/proftpd/bin/ftpdctl uses system library /lib/x86_64-linux-gnu/libcap.so.2 for libcap.so.2 /srv/slappart11/cqg/inst/test0-0/tmp/soft/728168be59c5353c6e3c6a6bc4cad052/parts/proftpd/libexec/mod_auth_web.so has some not found libraries:
    /srv/slappart11/cqg/inst/test0-0/tmp/soft/728168be59c5353c6e3c6a6bc4cad052/parts/proftpd/libexec/mod_auth_web.so: /usr/lib/x86_64-linux-gnu/libssl.so.1.1: version `OPENSSL_1_1_1' not found (required by /srv/slappart11/cqg/inst/test0-0/tmp/shared/curl/da798e87b4f10345c33fbae0a4593114/lib/libcurl.so.4)
    /srv/slappart11/cqg/inst/test0-0/tmp/soft/728168be59c5353c6e3c6a6bc4cad052/parts/proftpd/sbin/proftpd uses system library /lib/x86_64-linux-gnu/libcap.so.2 for libcap.so.2
    /srv/slappart11/cqg/inst/test0-0/tmp/soft/728168be59c5353c6e3c6a6bc4cad052/parts/proftpd/sbin/in.proftpd uses system library /lib/x86_64-linux-gnu/libcap.so.2 for libcap.so.2
    Ran 0 tests in 530.067s
    ----------------------------------------------------------------------

/reviewed-on nexedi/slapos!685

Because we were simply using "setupClass", all classes where storing
snapshots in the same folder, so if more than one class failed we also
had an error in storing snapshot.

/reviewed-on nexedi/slapos!683