Instead of referring to minor version of Centos, use the currently last
released one version 7.

/reviewed-on nexedi/slapos.package!30

There is no need to use absolute path to executable, as PATH environment
variable provide one and it is easy to be overriden by the user.

/reviewed-on nexedi/slapos.package!31

headers['Location'] might not exists, so get it with fallback to
nothing.

By using dict comparision with assertEqual the result will be presented
as diff between expected and found values. This allows test reader to
understand the reason of failing test, instead of trying to guess what
is really wrong with the deployed site.

"wendelin" key is used in many places in the playbook and slapos so it
is required to find infromation with this key.

Remove temporary directory after exection.

/reviewed-on nexedi/slapos.package!29

Instead of chosing arbitrary directory and removing, often not
accessible directories, use standard mktemp for temporary location.

/reviewed-on nexedi/slapos.package!28

Since "[playbook] Make Wendelin like ERP5" Wendelin became compatible
with ERP5 SR, so compilation detection script shall support it.

@rafael - that's last one of my pre-prepared work for playbooks. Here in order to hide "internal" variables of playbook (like `backend_url_path`) and reuse them between different playbooks.

/reviewed-on nexedi/slapos.package!27

Wrong tags were used.

There is no need to differentiate Wendelin from ERP5, as both can use
same cluster configuration, and only BT5 list is different.

The ERP5 software type changed to default, as create-erp5-site has been
implemented there.

Upgrading to tag 1.0.56 requires to update the software_type of ERP5 to default, as it happened with recent changes in slapos.git repository for ERP5.

Cc: @rafael - please feel free to push it to proper audience.

/reviewed-on nexedi/slapos.package!25

- compat level was missing
- keep debconf disabled
- skip shlibs

Plus some clean up.

  Changes are from slapos.git repository.

  Unfortunally exising keys from open build service uses 1028-bit keys and debian 9 seems not reconize is as
  security enough, so on debian 9, we allow insecure repositories to allow re6st-node package be installed.

  This change can be re-worked in order to make the repository valid again.

  Grandenet is only a re6stnet service of VIFIB

Since buildout 2 no longer supports using multiple versions of Python
in a single buildout, we're now forced to use slapos.rebootstrap.