Bash script

@westonruter What do you think ?
It probably doesn't matter, does it? And actually, some of the sites we're looking at upgrading have a build step that puts the WordPress files, themes, and plugins into the webroot. So that's a bit tricky, and I'm not sure we can generalize that part of it. Might need to just operate within the context of the build, and then if it succeeds, do an site-specific `rsync` from the build directory over to the source directories.