Add support for bbr backups of ATC

[matthewfischer]

Add support to backup ATC in an operations file. The backup would be performed by bbr by the operator.

[matthewfischer]

Testing:

jumpbox/0:~$ bbr deployment --target https://10.0.0.6:25555 --username admin --password XXXXXXX --deployment concourse-bosh --ca-cert bosh_ca.crt b
[bbr] 2018/06/12 21:55:46 INFO - Looking for scripts
[bbr] 2018/06/12 21:55:47 INFO - db/dafbf6d0-a468-4509-ab46-43354e59c4eb/bbr-atcdb/backup
[bbr] 2018/06/12 21:55:47 INFO - db/dafbf6d0-a468-4509-ab46-43354e59c4eb/bbr-atcdb/restore
[bbr] 2018/06/12 21:55:49 INFO - Running pre-checks for backup of concourse-bosh...
[bbr] 2018/06/12 21:55:50 INFO - Starting backup of concourse-bosh...
[bbr] 2018/06/12 21:55:50 INFO - Running pre-backup-lock scripts...
[bbr] 2018/06/12 21:55:50 INFO - Finished running pre-backup-lock scripts.
[bbr] 2018/06/12 21:55:50 INFO - Running backup scripts...
[bbr] 2018/06/12 21:55:50 INFO - Backing up bbr-atcdb on db/dafbf6d0-a468-4509-ab46-43354e59c4eb...
[bbr] 2018/06/12 21:55:50 INFO - Finished backing up bbr-atcdb on db/dafbf6d0-a468-4509-ab46-43354e59c4eb.
[bbr] 2018/06/12 21:55:50 INFO - Finished running backup scripts.
[bbr] 2018/06/12 21:55:50 INFO - Running post-backup-unlock scripts...
[bbr] 2018/06/12 21:55:50 INFO - Finished running post-backup-unlock scripts.
[bbr] 2018/06/12 21:55:50 INFO - Copying backup -- 116K uncompressed -- from db/dafbf6d0-a468-4509-ab46-43354e59c4eb...
[bbr] 2018/06/12 21:55:50 INFO - Finished copying backup -- from db/dafbf6d0-a468-4509-ab46-43354e59c4eb...
[bbr] 2018/06/12 21:55:50 INFO - Starting validity checks -- from db/dafbf6d0-a468-4509-ab46-43354e59c4eb...
[bbr] 2018/06/12 21:55:50 INFO - Finished validity checks -- from db/dafbf6d0-a468-4509-ab46-43354e59c4eb...
[bbr] 2018/06/12 21:55:50 INFO - Backup created of concourse-bosh on 2018-06-12 21:55:50.480110573 +0000 UTC m=+4.461602980

[vito]

thanks!