Move Firehose JS client into npm package

[bradgessler]

Break the JS code out of https://github.com/firehoseio/firehose/tree/master/lib/assets/javascripts to https://github.com/firehoseio/firehose/javascript and package up as an NPM package (firehose is taken, so firehose-client?)

[bradgessler]

@steel this issue may be relevant to some of the front end work you're doing.

[steel]

👍

[bakkdoor]

We should probably merge / base these changes off of the client-side dropped messages callback feature I did as part of #52
See https://github.com/firehoseio/firehose/tree/dropped-messages-callback

[steel]

@bakkdoor can your branch be merged into master?

[steel]

@bradgessler how do you feel about moving the js client out into a separate repo? I can't get TravisCI to run both ruby and js specs easily in 1 go. Plus, I don't think it makes sense to.

[bakkdoor]

@steel Yeah, I'm going to merge it into master now

[bradgessler]

We'll have to deprecate https://github.com/firehoseio/firehose/blob/master/lib/firehose/cli.rb#L17-L20 in that release. I'm happy with something like:

puts "DEPRECATED: Firehose JavaScripts are now available at https://github.com/firehoseio/..."

[steel]

Moved everything over to https://github.com/firehoseio/js_client and published 1.0

[steel]

We need to deprecate the JS in this repo.