Fix error: `subprocess.CalledProcessError: Command

Fix the following failing skopeo call:
'skopeo copy docker://ubuntu:latest/ dir://tmp/tmpyFFP9Wvirt-bootstrap'

The function `tempfile.mkdtemp()` returns full path and do not need additional
slash at the beginning. Thus the destination path is incorrect.

`dir://tmp/tmpyFFP9Wvirt-bootstrap`
-----^

it should be:

`dir:/tmp/tmpyFFP9Wvirt-bootstrap`
-----^

1 files changed, 1 insertions, 1 deletions

diff --git a/sources.py b/sources.py
index 4e98610..7045a29 100644
--- a/sources.py
+++ b/sources.py
@@ -68,7 +68,7 @@ class DockerSource:
             #       folders for broader enablement
             cmd = ["skopeo", "copy",
                    "docker://%s/%s" % (self.registry, self.image),
-                   "dir:/%s" % tmpDest]
+                   "dir:%s" % tmpDest]
             if self.insecure:
                 cmd.append('--src-tls-verify=false')
             if self.username: