Generate concourse secrets in pipeline
Generate concourse secrets in pipeline

Previously concourse only used a predefined password that was passed
at pipeline creation. Now we generate a new secrets file that we
store in S3. It is provided to the new build_manifest.sh script.

alphagov/paas-cf,alphagov/paas-cf,jimconner/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,jimconner/paas-cf,alphagov/paas-cf,jimconner/paas-cf,jimconner/paas-cf,jimconner/paas-cf,alphagov/paas-cf,alphagov/paas-cf,jimconner/paas-cf,jimconner/paas-cf