Update README.md

README.md

-GeoPHP is a open-source native PHP library for doing geometry operations. It is written entirely in PHP and 
+[![Build Status](https://travis-ci.org/phayes/geoPHP.svg?branch=master)](https://travis-ci.org/phayes/geoPHP)
+
+GeoPHP is a open-source native PHP library for doing geometry operations. It is written entirely in PHP and 
 can therefore run on shared hosts. It can read and write a wide variety of formats: WKT (including EWKT), WKB (including EWKB), GeoJSON, 
 KML, GPX, GeoRSS). It works with all Simple-Feature geometries (Point, LineString, Polygon, GeometryCollection etc.)
 and can be used to get centroids, bounding-boxes, area, and a wide variety of other useful information.