add travis build status to readme file

Author: q4a

.gitignore

@@ -10,7 +10,6 @@ bin_plugs/
 intermediate/
 intermediate_plugs/
 lib/
-src/Externals/
 *.aps
 *.user
 *.PVS-Studio.*

README.md

@@ -1,6 +1,13 @@
-X-Ray Engine 1.6 expansion [![Build status](https://ci.appveyor.com/api/projects/status/16mp39v0d7fts6yf?svg=true)](https://ci.appveyor.com/project/OpenXRay/xray-16)
+X-Ray Engine 1.6 expansion
 ==========================
 
+### Build Status:
+
+|Platform|Build Status|
+|--------|------|
+| Linux x64 |[![Build Status](https://api.travis-ci.org/OpenXRay/xray-16.svg?branch=xd_dev)](https://travis-ci.org/OpenXRay/xray-16)|
+| Windows |[![Build status](https://ci.appveyor.com/api/projects/status/16mp39v0d7fts6yf?svg=true)](https://ci.appveyor.com/project/OpenXRay/xray-16)|
+
 This repository contains X-Ray Engine sources based on version 1.6.02.
 The original engine is used in S.T.A.L.K.E.R. Call of Pripyat game released by GSC Game World.