Fix missing argument error

Fix the error message argument "quiet" is missing, with no default by adding quiet with default value FALSE to the install_git function just like it has been done with the install_github function

Author: StevenMMortimer

R/install-git.r

@@ -10,6 +10,7 @@
 #' @param branch Name of branch or tag to use, if not master.
 #' @param credentials A git2r credentials object passed through
 #'   to \code{\link[git2r]{clone}}.
+#' @param quiet if \code{TRUE} suppresses output from this function.
 #' @param ... passed on to \code{\link{install}}
 #' @export
 #' @family package installation
@@ -18,12 +19,12 @@
 #' install_git("git://github.com/hadley/stringr.git")
 #' install_git("git://github.com/hadley/stringr.git", branch = "stringr-0.2")
 #'}
-install_git <- function(url, subdir = NULL, branch = NULL, credentials = NULL, ...) {
+install_git <- function(url, subdir = NULL, branch = NULL, credentials = NULL, quiet=FALSE, ...) {
 
   remotes <- lapply(url, git_remote, subdir = subdir,
                     branch = branch, credentials=credentials)
 
-  install_remotes(remotes, ...)
+  install_remotes(remotes, quiet = quiet, ...)
 }
 
 git_remote <- function(url, subdir = NULL, branch = NULL, credentials=NULL) {