Make local provider bootstrap and destroy remove clone template files
Do not remove lock file when bootstrapping
Fix tests
Merge pull request #452 from wallyworld/remove-lock-dirs

Make local provider bootstrap and destroy remove clone template files

Fixes: lp:1351004

Juju with the new flock implementation doesn't care, but forcibly destroying a local environment can leave the lock dirs around. Then if a downgrade is done, the older juju which still uses fslock thinks the lock is still held and won't start containers. This fix removes any lock files when local provider is bootstrapped and destroyed.