Add master build status

Author: fpistm

README.md

@@ -1,5 +1,7 @@
 # Arduino core support for STM32 based boards
-### Latest release [![GitHub release](https://img.shields.io/github/release/stm32duino/Arduino_Core_STM32.svg)](https://github.com/stm32duino/Arduino_Core_STM32/releases/latest) [![GitHub commits](https://img.shields.io/github/commits-since/stm32duino/Arduino_Core_STM32/1.3.0.svg)](https://github.com/stm32duino/Arduino_Core_STM32/compare/1.3.0...master)
+[![GitHub release](https://img.shields.io/github/release/stm32duino/Arduino_Core_STM32.svg)](https://github.com/stm32duino/Arduino_Core_STM32/releases/latest)
+[![GitHub commits](https://img.shields.io/github/commits-since/stm32duino/Arduino_Core_STM32/1.3.0.svg)](https://github.com/stm32duino/Arduino_Core_STM32/compare/1.3.0...master)
+[![Build Status](https://travis-ci.com/stm32duino/Arduino_Core_STM32.svg?branch=master)](https://travis-ci.com/stm32duino/Arduino_Core_STM32)
 
 **Warning**: release versioning has been changed from date versioning to semantic one. See [Release Versioning change](https://github.com/stm32duino/wiki/wiki/Release-Versioning-change)
 
@@ -63,14 +65,14 @@ For advanced user, you can use the repository: see the [Using git repository](ht
   * STM32L4
     * [Nucleo L432KC](http://www.st.com/en/evaluation-tools/nucleo-l432kc.html)
     * [Nucleo L476RG](http://www.st.com/en/evaluation-tools/nucleo-l476rg.html)
-    * [Nucleo-L496ZG](http://www.st.com/en/evaluation-tools/nucleo-l496zg.html)
-    * [Nucleo-L496ZG-P](http://www.st.com/en/evaluation-tools/nucleo-l496zg-p.html)
+    * [Nucleo L496ZG](http://www.st.com/en/evaluation-tools/nucleo-l496zg.html)
+    * [Nucleo L496ZG-P](http://www.st.com/en/evaluation-tools/nucleo-l496zg-p.html)
     * [B-L475E-IOT01A](http://www.st.com/en/evaluation-tools/b-l475e-iot01a.html)
 
 ### Next release
   * STM32L4
     * [Nucleo L4R5ZI](http://www.st.com/en/evaluation-tools/nucleo-l4r5zi.html)
-    * [Nucleo-L4R5ZI-P](http://www.st.com/en/evaluation-tools/nucleo-l4r5zi-p.html)
+    * [Nucleo L4R5ZI-P](http://www.st.com/en/evaluation-tools/nucleo-l4r5zi-p.html)