Don't fetch unneeded ES fields and don't serialize unneeded nested items.

[nonword]

This PR amends three things to improve response time:

1. Adds compression library to automatically gzip all responses.
2. Adds _source.excludes param to search and fetchById resources calls to exclude unnecessary source fields in ES response
3. Truncates bib items to 10 in a search context. Seems front-end is only displaying first now anyway. (Will need to build way to paginate through nested items in future after indexing them as nested datatype.)

[nonword]

I think this PR may mitigate some of the issues with many-item bibs slowing down some searches. For your consideration @nodanaonlyzuul

[nodanaonlyzuul]

Okay! I'll take a look and so some very unscientific benchmarking. Phone. Brevity. Typos.

…

On Jul 21, 2017 5:41 PM, "Paul Beaudoin" ***@***.***> wrote: I think this PR may mitigate some of the issues with many-item bibs slowing down some searches. For your consideration @nodanaonlyzuul <https://github.com/nodanaonlyzuul> — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#54 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAAiG5Gx30Z2KszpOZe7zNK3G7cs6TWdks5sQRr1gaJpZM4OUj2h> .

[kfriedman]

Great to add gzip. I'm a little concerned that the API Gateway might not support it, but I'm pretty sure it does now.

Also, it might be better to let Nginx handle the gzipping as I think that's best practice. We'd have to update the Beanstalk configuration. Maybe something like: https://gist.github.com/omidfi/aaae08617729d26fce52024cafb59e12

[nodanaonlyzuul]

I agree with Kevin. I'm going to open an issue about letting nginx handle gzip.
I'm going to keep this PR open for the other functionality and maybe we can remove gzip from this feature branch.

[nonword]

Removed app level gzip compression

[nonword]

The useful parts of this have been folded into #99