Use build badges provided by Gitlab (#3915)

Author: UdjinM6

README.md

@@ -1,7 +1,9 @@
 Dash Core staging tree 0.17
 ===========================
 
-`master:` [![Build Status](https://travis-ci.org/dashpay/dash.svg?branch=master)](https://travis-ci.org/dashpay/dash) `develop:` [![Build Status](https://travis-ci.org/dashpay/dash.svg?branch=develop)](https://travis-ci.org/dashpay/dash/branches)
+|CI|master|develop|
+|-|-|-|
+|Gitlab|[![Build Status](https://gitlab.com/dashpay/dash/badges/master/pipeline.svg)](https://gitlab.com/dashpay/dash/-/tree/master)|[![Build Status](https://gitlab.com/dashpay/dash/badges/develop/pipeline.svg)](https://gitlab.com/dashpay/dash/-/tree/develop)|
 
 https://www.dash.org