Don't skip files when checking for root folder

Submodules don't have a .git folder, but only a file.
Fixes #7

src/helpers.rs

@@ -49,7 +49,10 @@ pub struct BoilerplateOpts {
     pub timestamp: Option<stderrlog::Timestamp>,
 }
 
-/// Checks if the given dir contains the root `.git` dir
+/// Checks if the given dir contains the root `.git` dir or file
+///
+/// Submodules do not contain a complete .git directory, but only a .git file with a reference to
+/// the actual folder. This function takes both into account.
 ///
 /// # Errors
 ///
@@ -60,13 +63,6 @@ fn has_git_dir(path: &PathBuf) -> Result<bool> {
     git.push(".git");
     for entry in path.read_dir().chain_err(|| "Reading contents of dir")? {
         if let Ok(entry) = entry {
-            // skip non-directories
-            if let Ok(ft) = entry.file_type() {
-                if !ft.is_dir() {
-                    continue;
-                }
-            }
-
             // check if this is `.git`
             if entry.path() == git {
                 return Ok(true);