osbuilder: move code into tools directory

move all osbuilder files into `tools` directory to be able
to merge this into kata-containers repo.

Signed-off-by: Salvador Fuentes <salvador.fuentes@intel.com>

tools/osbuilder/image-builder/Dockerfile

@@ -0,0 +1,10 @@
+#
+# Copyright (c) 2018 Intel Corporation
+#
+# SPDX-License-Identifier: Apache-2.0
+
+From docker.io/fedora:latest
+
+RUN [ -n "$http_proxy" ] && sed -i '$ a proxy='$http_proxy /etc/dnf/dnf.conf ; true
+
+RUN dnf install -y qemu-img parted gdisk e2fsprogs gcc xfsprogs findutils