Free memory in git2go library

Fix memory leak in jiri which was causing crash in libgit2 code

Change-Id: If3046d115d11907d6fda7ff7972f466efaf62187
diff --git a/git/git.go b/git/git.go
index c7064bb..0c8dc98 100644
--- a/git/git.go
+++ b/git/git.go
@@ -163,6 +163,7 @@
 	if err != nil {
 		return false, err
 	}
+	defer repo.Free()
 	opts := &git2go.StatusOptions{}
 	opts.Show = git2go.StatusShowIndexAndWorkdir
 	opts.Flags = git2go.StatusOptIncludeUntracked
@@ -193,6 +194,7 @@
 	if err != nil {
 		return false, err
 	}
+	defer repo.Free()
 	opts := &git2go.StatusOptions{}
 	opts.Show = git2go.StatusShowIndexAndWorkdir