Tests: document ports required for tests.

README

diff --git a/README b/README
index 8f2f8d0..c364b98 100644
--- a/README
+++ b/README
@@ -5,6 +5,9 @@
 
 Note: some tests may fail since they are for bugs not fixed in public code.
 
+Note: tests run nginx listening on localhost, and currently this includes
+following ports: 8080, 10025, 10026.
+
 Currently each test creates it's own temporary directory and uses it for
 logs etc.  One may instruct tests not to remove the temp directory (e.g.
 for analysis of failed test) by setting LEAVE environment variable.