Readme: Make status badges consistent again

README.md

@@ -1,7 +1,7 @@
 OpenMW
 ======
 
-[![Build Status](https://img.shields.io/travis/OpenMW/openmw.svg?style=plastic)](https://travis-ci.org/OpenMW/openmw) [![Coverity Scan Build Status](https://scan.coverity.com/projects/3740/badge.svg)](https://scan.coverity.com/projects/3740)
+[![Build Status](https://img.shields.io/travis/OpenMW/openmw.svg)](https://travis-ci.org/OpenMW/openmw) [![Coverity Scan Build Status](https://scan.coverity.com/projects/3740/badge.svg)](https://scan.coverity.com/projects/3740)
 
 OpenMW is an attempt at recreating the engine for the popular role-playing game
 Morrowind by Bethesda Softworks. You need to own and install the original game for OpenMW to work.