Index status in dashboard should reflect the state of the indexes in addition to the state of the nodes (was: Indexer not functioning, rebalance says "successful" but still allows button to be pressed)

[edit - sorry, forgot to gather screenshots before shutting down]

Vulcan build 1849

A couple issues that need some investigation:

1 - The indexer doesn't seem to be functioning properly but there is no indication in the UI logs.  All I can see is that the list of indexes is flashing red yet the "index service" on the dashboard is showing green.  Rob Ashcom

2 - The rebalance button is showing active, and in fact initiates a rebalance when pressed, the rebalance says that it completed "successfully", but then the button remains active again. Dave Finlay

3 - The travel-sample says it failed: Loading sample bucket travel-sample failed: {failed_to_load_samples_with_status,
1} Mike Wiederhold [X]

Logs are at:

https://s3.amazonaws.com/cb-engineering/perry/travelsamplefailed/collectinfo-2018-02-13T145604-ns_1%40ec2-34-224-4-211.compute-1.amazonaws.com.zip
https://s3.amazonaws.com/cb-engineering/perry/travelsamplefailed/collectinfo-2018-02-13T145604-ns_1%40ec2-54-197-77-200.compute-1.amazonaws.com.zip
https://s3.amazonaws.com/cb-engineering/perry/travelsamplefailed/collectinfo-2018-02-13T145604-ns_1%40ec2-54-209-15-231.compute-1.amazonaws.com.zip