funcs for setting up ElasticSearch backups and making snapshots
instructions for posting organization,repository data to ES

This will eventually be a command but needs to be stored somewhere
for now.
Merge branch '137-browse-ui' of https://github.com/densho/ddr-cmdln into 137-browse-ui
use the correct variable name
pass models_dir to elasticsearch._create_index(); update example
fix typo in repo/org indexing example
add "public" arg to ddrindex command