deploy failed

[WeiZhang418]

Hi, imfly,

After I forked your project down, I followed readme.md's instructions. When I typed "gulp deploy", it said some files were staged in the index: "
[10:51:05] Using gulpfile ~/projects/sacdl-project/gulpfile.js
[10:51:05] Starting 'watch'...
[10:51:05] Finished 'watch' after 17 ms
[10:51:05] Starting 'clean'...
[10:51:05] Finished 'clean' after 16 ms
[10:51:05] Starting 'js'...
[10:51:05] Starting 'css'...
[10:51:05] Starting 'images'...
[10:51:05] Starting 'fonts'...
[10:51:05] Starting 'html'...
[10:51:05] Finished 'html' after 4 ms
[10:51:05] gulp-imagemin: Minified 0 images
[10:51:05] Finished 'images' after 22 ms
[10:51:06] Finished 'css' after 452 ms
[10:51:06] Finished 'js' after 473 ms
[10:51:06] Finished 'fonts' after 446 ms
[10:51:06] Starting 'default'...
[10:51:06] Finished 'default' after 5.51 μs
[10:51:06] Starting 'deploy'...
[10:51:06] [gh-pages] Cloning repo
[10:51:06] [gh-pages] Checkout branch gh-pages
[10:51:06] [gh-pages] Updating repository
[10:51:07] 'deploy' errored after 1.27 s
[10:51:07] Error in plugin 'gulp-gh-pages'
Message:
Command failed: /bin/sh -c git rm -r .
error: the following files have changes staged in the index:
css/app.min.css
css/bootstrap.min.css
js/app.min.js
js/d3.min.js
js/sacdl.min.js
(use --cached to keep the file, or -f to force removal)

Details:
killed: false
code: 1
signal: null
cmd: /bin/sh -c git rm -r .
^C
"
I don't know how to deal with it. Could you help me ? Thanks