Add Travis build status

Denis Ivanov · web-flow · commit a6b8913ee0ec · 2018-01-05T12:56:53.000+03:00
diff --git a/README.md b/README.md
@@ -1,2 +1,3 @@
 XPath support for AngleSharp
 
+[![Build Status](https://travis-ci.org/denis-ivanov/AngleSharp.XPath.svg?branch=master&style=flat-square)](https://travis-ci.org/denis-ivanov/AngleSharp.XPath)

Original file line number	Diff line number	Diff line change
`@@ -1,2 +1,3 @@`
`1`	`1`	`XPath support for AngleSharp`
`2`	`2`
	`3`	`+[![Build Status](https://travis-ci.org/denis-ivanov/AngleSharp.XPath.svg?branch=master&style=flat-square)](https://travis-ci.org/denis-ivanov/AngleSharp.XPath)`