test: add DNS, File, and HTTP server test scripts

test_dns.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+# Test DNS server on port 5300
+dig @127.0.0.1 -p 5300 example.com

test_file.sh

@@ -0,0 +1,4 @@
+#!/bin/sh
+# Test File server on port 9090
+# Send file name "test.txt" to server and print response
+echo "test.txt" | nc 127.0.0.1 9090

test_http.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+# Test HTTP server on port 8080
+curl -v http://127.0.0.1:8080/