README: use SVG for Travis-CI badge

TooTallNate · TooTallNate · commit 4ea42bf3dce5 · 2015-07-10T17:48:38.000-07:00
diff --git a/README.md b/README.md
@@ -1,7 +1,7 @@
 https-proxy-agent
 ================
 ### An HTTP(s) proxy `http.Agent` implementation for HTTPS
-[![Build Status](https://travis-ci.org/TooTallNate/node-https-proxy-agent.png?branch=master)](https://travis-ci.org/TooTallNate/node-https-proxy-agent)
+[![Build Status](https://travis-ci.org/TooTallNate/node-https-proxy-agent.svg?branch=master)](https://travis-ci.org/TooTallNate/node-https-proxy-agent)
 
 This module provides an `http.Agent` implementation that connects to a specified
 HTTP or HTTPS proxy server, and can be used with the built-in `https` module.
