[pyramid] Drop warning about pyramid_debugtoolbar not found in debug mode Some people way want to run a pyramid server in debug mode without the toolbar. This warning is annoying for them. Others should just install and *include* the toolbar by hand.

[pkg] Add development.ini.tmpl to "cubicweb.pyramid" package data Otherwise the file is not installed and `cubicweb-ctl create -c pyramid` does not work.

[skeleton] Don't use system site packages in tox environment As we changed this in cubicweb, there is a consensus that this is not the best practice so let us change it as well for skeleton.