Add a basic test case for unix jails

bin/varnishtest/tests/README

@@ -19,6 +19,7 @@ Naming scheme
 	id ~ [d] --> Director VMOD tests
 	id ~ [e] --> ESI tests
 	id ~ [g] --> GZIP tests
+	id ~ [j] --> JAIL tests
 	id ~ [l] --> VSL tests
 	id ~ [m] --> VMOD tests excluding director
 	id ~ [p] --> Persistent tests

bin/varnishtest/tests/j00000.vtc

+varnishtest "Code coverage basic UNIX jail"
+
+feature user_varnish
+feature group_varnish
+feature root
+
+server s1 {
+	rxreq
+	txresp
+} -start
+
+varnish v1 \
+	-jail "-junix,user=varnish,ccgroup=varnish" \
+	-vcl+backend {
+} -start
+
+client c1 {
+	txreq
+	rxresp
+	expect resp.status == 200
+} -run