Fallback to default branch when cloning instead of parsing

pkg/repo/repo.go

@@ -32,7 +32,7 @@ type CloneOpts struct {
 	Path           string // TODO: should Path be a part of clone opts?
 	Branch         string
 	Quiet          bool
-	IgnoreExisting bool // TODO: implement!
+	IgnoreExisting bool
 }
 
 func Clone(opts *CloneOpts) (*Repo, error) {
@@ -51,6 +51,10 @@ func Clone(opts *CloneOpts) (*Repo, error) {
 		}
 	}
 
+	if opts.Branch == "" {
+		opts.Branch = cfg.DefBranch
+	}
+
 	// If branch name is actually a tag (ie. is prefixed with refs/tags) - check out that tag.
 	// Otherwise, assume it's a branch name and check it out.
 	refName := plumbing.ReferenceName(opts.Branch)