Fix building status icon url

README.md

@@ -348,7 +348,7 @@ See also [A comparison of operating systems written in Rust](https://github.com/
 * [whitfin/s3-utils](https://github.com/whitfin/s3-utils) - A small tool containing utilities based around Amazon S3 to provide additional convenience APIs.
 * [fcsonline/tmux-thumbs](https://github.com/fcsonline/tmux-thumbs) — A lightning fast version of tmux-fingers written in Rust, copy/pasting tmux like vimium/vimperator.
 * [amar-laksh/workstation](https://github.com/amar-laksh/workstation) — A commandline tool to help you manage your workstation by distancing you from your screen, locking your screen when you aren't there among other things with OPENCV!
-* [guoxbin/dtool](https://github.com/guoxbin/dtool) - A useful command-line tool collection to assist development including conversion, codec, hashing, encryption, etc. [![Build Status](https://travis-ci.org/guoxbin/dtool.svg?branch=master)](https://travis-ci.org/guoxbin/dtool)
+* [guoxbin/dtool](https://github.com/guoxbin/dtool) - A useful command-line tool collection to assist development including conversion, codec, hashing, encryption, etc. [![Build Status](https://api.travis-ci.org/guoxbin/dtool.svg?branch=master)](https://travis-ci.org/guoxbin/dtool)
 
 ### Video