Test non-"web_*" roles for nginx config
Historically, we named roles involving a web server "web_*", and this
still makes sense for roles that are "mostly a webserver" like
web_static and web_jekyll.
However, some roles (for example mailman3 and matrix) are "lots of
things, and a webserver as side job". Forcing them into the web_* name
scheme wouldn't make sense IMHO.
Therefore change test_nginx.sh to test all roles instead of only web_*
Note that "all roles" sounds more than it is. The script greps
pillar/role/$role.sls for "nginx", so in practise it will still only
test roles that actually include nginx config in their pillar data.