Because unfortunately $RefParser does not support global $ref:

https://github.com/APIDevTools/json-schema-ref-parser/issues/145

* master: (34 commits)
  software/end-to-end-testing: remove pattern from input schema
  stack/slapos: version up slapos.core 1.10.8
  software/end-to-end-testing: add end-to-end-testing software Use runTestSuite interface to launch tests that request instances on actual SlapOS cloud.
  python-xmlsec: install setuptools-scm as wheel (fix python3 install)
  component/xmlsec: version up 1.2.37 ( on py3 only )
  software/fluentd/test: adjust test for msgpack >= 1.0
  component/zodbtools: remove profiles for ZODB4* tests on python3
  software/slapos-testing: remove redundant eggs
  *: only install backports-lzma on python2
  stack/erp5: backport DateTime fixes
  component/nodejs: remove unused 8.9.4
  software/dream: remove useless version pins
  software/dream: pin dream repository revision
  software/dream: use current nodejs version
  software/dream: follow buildout naming conventions for section names
  pygolang: Unbreak tests
  ZEO: Fix ZEO4-wc2 installation, take2
  wendelin.core: tests: Pin ZopeUndo
  wendelin.core: Unbreak tests
  software/ors-amarisoft: update changelog
  ...

See merge request nexedi/slapos!1486