Ensure local spell dir is empty before downloading (#122)
Ensure local spell dir is empty before downloading (#122)

Untarring the downloaded spell did not remove pre-existing files,
meaning that files that were removed in the upstream spell would stick
around locally.

Signed-off-by: Michael McCracken <678f76d0129c6a47299e3c6abb92ed26d253a960@canonical.com>
ubuntu/conjure-up,Ubuntu-Solutions-Engineering/conjure,conjure-up/conjure-up,battlemidget/conjure-up,conjure-up/conjure-up,ubuntu/conjure-up,Ubuntu-Solutions-Engineering/conjure,battlemidget/conjure-up