I have a workflow in which I have plenty of non-committed files in my working directory: project files for my IDE, ngrok copy, WIP for stuff, etc.
Running git add --all in https://github.com/liip/RMT/blob/master/src/Liip/RMT/VCS/Git.php#L70 is bad and should be discouraged.
Please at least permit a list of files to be provided.