enable sockopt tests

.travis.yml

@@ -9,6 +9,7 @@ before_script:
 - uname -a
 - sudo ntpdate -u time.google.com
 - date
+- sudo setcap cap_net_admin=eip ${GOROOT}/bin/go
 script:
 - go test -p 1 -tags json -v v2ray.com/core/...
 after_success:

shippable.yml

@@ -15,6 +15,7 @@ build:
     - tar -C /usr/local -xzf golang.tar.gz
     - export PATH=$PATH:/usr/local/go/bin
     - export GOPATH=/v2ray
+    - sudo setcap cap_net_admin=eip /usr/loca/go/bin/go
     - go get v2ray.com/core/...
     - go get v2ray.com/ext/...
     - go test -p 1 -v v2ray.com/core/...

transport/internet/sockopt_linux_test.go

@@ -12,8 +12,6 @@ import (
 )
 
 func TestSockOptMark(t *testing.T) {
-	t.Skip("requires CAP_NET_ADMIN")
-
 	tcpServer := tcp.Server{
 		MsgProcessor: func(b []byte) []byte {
 			return b