add a few example scripts

scripts/auth.lua

@@ -0,0 +1,18 @@
+-- example script that demonstrates response handling and
+-- retrieving an authentication token to set on all future
+-- requests
+
+token = nil
+path  = "/authenticate"
+
+request = function()
+   return wrk.format("GET", path)
+end
+
+response = function(status, headers, body)
+   if not token and status == 200 then
+      token = headers["X-Token"]
+      path  = "/resource"
+      wrk.headers["X-Token"] = token
+   end
+end