Fixed error updating HEAD when cloning a repo.

GetHeadBranch() used to return a string of the Branch name, but now
returns a type Branch (which is the Refspec, not the name.) The
reset call wasn't updated, and was duplicating the refs/heads/ portion of
the filename.

Fixes #5

cmd/reset.go

@@ -56,7 +56,7 @@ func Reset(c *git.Client, args []string) {
 		//  git reset [mode] commit
 		// First, update the head reference for all modes
 		branchName := c.GetHeadBranch()
-		err := c.GitDir.WriteFile(git.File("refs/heads/"+branchName),
+		err := c.GitDir.WriteFile(git.File(branchName.String()),
 			[]byte(fmt.Sprintf("%s", commitId)),
 			0644,
 		)

git/refspec.go

@@ -34,6 +34,10 @@ func (r RefSpec) Value(c *Client) (string, error) {
 // Use GetBranch to get a valid branch from a branchname, don't cast from string
 type Branch RefSpec
 
+// Implements Stringer on Branch
+func (b Branch) String() string {
+	return RefSpec(b).String()
+}
 // Returns a valid Branch object for an existing branch.
 func GetBranch(c *Client, branchname string) (Branch, error) {
 	b := Branch("refs/heads/" + branchname)