Desired git reference. Could be a commit, tag,
or branch name. Defaults to "master".
subdir
A subdirectory in the repository that
contains the app. By default, this function will run an
app from the top level of the repo, but you can use a
path such as `"inst/shinyapp".
port
The TCP port that the application should
listen on. Defaults to choosing a random port.
launch.browser
If true, the system's default web
browser will be launched automatically after the app is
started. Defaults to true in interactive sessions only.