More unit tests

fs.go

@@ -14,7 +14,7 @@ type (
 	}
 )
 
-// It returns a http.Filesystem that can be used by http.FileServer(). It is used interally
+// Dir returns a http.Filesystem that can be used by http.FileServer(). It is used interally
 // in router.Static().
 // if listDirectory == true, then it works the same as http.Dir() otherwise it returns
 // a filesystem that prevents http.FileServer() to list the directory files.
@@ -22,9 +22,8 @@ func Dir(root string, listDirectory bool) http.FileSystem {
 	fs := http.Dir(root)
 	if listDirectory {
 		return fs
-	} else {
-		return &onlyfilesFS{fs}
 	}
+	return &onlyfilesFS{fs}
 }
 
 // Conforms to http.Filesystem