[devtools] set .config in setUpClass instead of using a cache in a classproperty
This is much clearer and avoid problem with py.test introspection that triggered
creation and caching of the configuration before actual test execution. This
caused pb in unittest_postgres.PostgresStatementTimeoutTC where configuration
was built before module's setup, hence source configuration was missing
information about where to find the pg cluster.
Document: cubicweb-doc
Title: CubicWeb documentation
Author: Logilab
Abstract: Some base documentation for CubicWeb users and developpers
Section: Apps/Programming
Format: HTML
Index: /usr/share/doc/cubicweb-documentation/html/index.html
Files: /usr/share/doc/cubicweb-documentation/html/*