Add "host" flag to CLI index command

[jakewrfoster]

Overview:

It would be helpful for testing purposes to be able to index to a different ES host than is indicated by a given site's SearchPress settings. This would allow for new indexes to be tested in non-production cluster prior to changes that might be made to a production cluster.

Proposed User story:

As a user initiating an index operation from the SearchPress CLI, I should be able to indicate the target host for the index operation.

Proposed MVP:

• Add a "host" flag to the CLI index command

[mboynes]

Might also want an --index param as well, since you might want to push data to a different index on the same host

[jakewrfoster]

I thought the same, but ultimately decided that this should be in a new issue. I will write that up now - thanks!

[jakewrfoster]

The above can be tracked in: #134

[kjbenk]

I am going to look at implementing a solution for this over the next few days.