introduce RenderedTemplatesWriter to write the rendered templates to disk
Remove unused mixin

Confirmed that RunsCommands is not used by bosh_vcloud_cpi, the only
external gem that depends on bosh code.

Signed-off-by: Abhijit Hiremagalur <abhi@pivotallabs.com>
Introduce NullBlobstoreClient

This client helps us wire in storing rendered templates in the director
blobstore until we're finished implementing cleanup.

Signed-off-by: Abhijit Hiremagalur <abhi@pivotallabs.com>
wire in CompressedRenderedJobTemplates

Temporarily uploads a fake archive to the null blobstore

[#60724646]

Signed-off-by: Abhijit Hiremagalur <abhi@pivotallabs.com>