Add integration test script.

script/test.sh

@@ -0,0 +1,40 @@
+#!/bin/bash
+
+cd "$( dirname "${BASH_SOURCE[0]}" )/.."
+
+PROXY_ADDR=127.0.0.1:8888
+
+./cow -rc ~/.cow/debugrc -listen=$PROXY_ADDR &
+cow_pid=$!
+sleep 0.5
+
+test_get() {
+    local url
+    url=$1
+
+    # get 5 times
+    for i in {1..2}; do
+        if ! curl -L -s -x $PROXY_ADDR $SOCKS $url >/dev/null 2>&1; then
+            echo "=============================="
+            echo "GET $url FAILED!!!"
+            echo "=============================="
+            kill -SIGINT $server_pid
+            kill -SIGINT $local_pid
+            kill -SIGTERM $cow_pid
+            exit 1
+        fi
+        sleep 0.5
+    done
+    echo "=============================="
+    echo "GET $url passed"
+    echo "=============================="
+}
+
+test_get baidu.com # baidu uses content-length
+test_get youku.com # 302 redirect
+test_get douban.com # 301 redirect
+test_get www.taobao.com # chunked encoding
+test_get https://www.twitter.com # builtin blocked site, 301 direct
+test_get openvpn.net # blocked site, all kinds of block method
+
+kill -SIGTERM $cow_pid