Reduce size of image in README (#184)

It seems like my previous changes in #182 didn't work, so I switched to these, which do seem to work.

Author: mrnugget

README.md

@@ -1,6 +1,6 @@
 # Sourcegraph CLI [![Build Status](https://travis-ci.org/sourcegraph/src-cli.svg)](https://travis-ci.org/sourcegraph/src-cli) [![Go Report Card](https://goreportcard.com/badge/sourcegraph/src-cli)](https://goreportcard.com/report/sourcegraph/src-cli)
 
-<img src="https://user-images.githubusercontent.com/3173176/43567326-3db5f31c-95e6-11e8-9e74-4c04079c01b0.png" style="max-width: 350px; float: right;" >
+<img src="https://user-images.githubusercontent.com/3173176/43567326-3db5f31c-95e6-11e8-9e74-4c04079c01b0.png" width=450 align=right>
 
 **Quick links**:
 - [Installation](#installation)