REGTEST: Adapt reg test doc files to vtest.

This is a first patch to switch from varnishtest to new standalone
varnish cache reg testing program: vtest.

More information may be found here:

https://github.com/vtest/VTest
https://varnish-cache.org/docs/trunk/reference/varnishtest.html
https://varnish-cache.org/docs/trunk/reference/vtc.html
2 files changed