Always answer empty list if deployments not ready

An empty deployments will cause json decode exception, and once
deployments=[] coming, it will trigger another refresh. Always answer
empty list when deployments not ready will solve above two issues.

Change-Id: Iaee3a3ef25cf9907aaefd941dcb316ecb25a29d6
Closes-Bug: #1298417
Disable check_uptodate.sh check in pep8

Running generate_sample.sh currently produces an invalid heat.conf.sample
due to bug #1288586.

This change disables the check_uptodate.sh in the tox pep8 so that the
gate-heat-pep8 job passes while we find a more appropriate solution.

Change-Id: Ib20c4f892df68f7112d969d801a18a1a5bfbd474
Related-Bug: #1288586
Merge "Always answer empty list if deployments not ready"