The template resources don't actually need to retain any state, so they
are good candidates to be data sources.
This includes a few tweaks to the acceptance tests -- now configured to
run as unit tests -- since it seems that they have been slightly broken
for a while now. In particular, the "update" cases are no longer tested
because updating is not a meaningful operation for a data source.
This adds a new resource to template to generate multipart cloudinit
configurations to be used with other providers/resources.
The resource has the ability gzip and base64 encode the parts.