cjdns: clean up before building
cjdns: clean up before building

We don't want the playbook to break everytime someone fat-fingers
file changes into the build directory.

License: MIT
Signed-off-by: Lars Gierth <a7f454432b0865c35643e2b81965ab19364a6177@systemli.org>

sroerick/infrastructure,davidar/infrastructure,ipfs/infrastructure,ipfs/infrastructure,davidar/infrastructure,sroerick/infrastructure