Private function that adds a package to the list of dependencies that will be installed on the Promote server
add.dependency(name, importName, src, version, install, auth_token, ref,
subdir)name of the package to be installed
name under which the package is imported (for a github package, this may be different from the name used to install it)
source that the package is installed from (CRAN or github)
version of the package
whether or not the package should be installed in the model image
a personal access token for github or gitlab repositories
The git branch, tag, or SHA of the package to be installed
The path to the repo subdirectory holding the package to be installed