download_version        Download a specified version of a CRAN package
github_pull             GitHub references
install_bioc            Install a development package from the
                        Bioconductor git repository
install_bitbucket       Install a package directly from Bitbucket
install_cran            Attempts to install a package from CRAN.
install_deps            Install package dependencies if needed.
install_dev             Install the development version of a package
install_git             Install a package from a git repository
install_github          Attempts to install a package directly from
                        GitHub.
install_gitlab          Install a package from GitLab
install_local           Install a package from a local file
install_svn             Install a package from a SVN repository
install_url             Install a package from a url
install_version         Install specific version of a package.
package_deps            Find all dependencies of a CRAN or dev package.
parse-git-repo          Parse a remote git repo specification
system_requirements     Query the system requirements for a package
                        (and its dependencies)
update_packages         Update packages that are missing or
                        out-of-date.
