[doc] add badge for crates.io and travis-ci

Author: lotabout

README.md

@@ -1,5 +1,7 @@
 **Rargs** is kind of `xargs` + `awk` with pattern matching support.
 
+![Crates.io](https://img.shields.io/crates/v/rargs.svg) [![Build Status](https://travis-ci.org/lotabout/rargs.svg?branch=master)](https://travis-ci.org/lotabout/rargs)
+
 ## Installation
 
 ### Using Cargo