This commit adds the ability to provision files locally.
This is useful for cases where TerraForm generates assets
such as TLS certificates or templated documents that need
to be saved locally.
- While output variables can be used to return values to
the user, it is not extremly suitable for large content or
when many of these are generated, nor is it practical for
operators to manually save them on disk.
- While `local-exec` could be used with an `echo`, this
provider works across platforms and do not require any
convoluted escaping.
