Currently, the http resource always executes locally, even when scanning
a remote machine with `--target` which leads to undesireable behavior.
This change adds the ability to remotely execute tests with curl. This
behavior is currently opt-in with the `enable_remote_worker` flag, but
will become the default behavior in InSpec 2.0. Deprecation warnings
are emitted if the user is scanning a remote target but has not opted
in to the new behavior.
Signed-off-by: Adam Leff <adam@leff.co>
