[gnome-sdk-images] Remove build dir after commit

[Alexander Larsson <alexl src gnome org>]

commit 82c1bfd5020237d9fe8e6681fb9f9fa61efc366f
Author: Alexander Larsson <alexl redhat com>
Date:   Thu Apr 7 13:30:58 2016 +0200

    Remove build dir after commit

 Makefile |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/Makefile b/Makefile
index b9931f6..e99c347 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,7 @@
 all: repo org.gnome.Sdk.json
        rm -rf sdk
        xdg-app-builder --ccache --require-changes --repo=repo --subject="build of org.gnome.Sdk, `date`" 
${EXPORT_ARGS} sdk org.gnome.Sdk.json
+       rm -rf sdk
 
 repo:
        ostree  init --mode=archive-z2 --repo=repo