Enable Gzip Compression

[kvanderhoek]

Environment:
Production: https://reference.elasticpath.com/ + Test browsers provided by Webpage Test and Google Page Speed.

Problem:
According to Webpage Test and Google Page Speed compression is not enabled on https://reference.elasticpath.com/

Steps to Reproduce:

1. Navigate to https://www.webpagetest.org or https://developers.google.com/speed/pagespeed/insights/
2. Type in our production URL: https://reference.elasticpath.com/

Observed Results:
Webpage Test
Use gzip compression for transferring compressable responses: 23/100
1,051.1 KB total in compressible text, target size = 240.9 KB - potential savings = 810.2 KB

FAILED - (551.7 KB, compressed = 147.8 KB - savings of 403.8 KB) - https://reference.elasticpath.com/vendors~app.js
FAILED - (409.6 KB, compressed = 62.4 KB - savings of 347.2 KB) - https://reference.elasticpath.com/app.js
FAILED - (28.3 KB, compressed = 2.0 KB - savings of 26.3 KB) - https://reference.elasticpath.com/cortex/?zoom=navigations:element,navigations:element:child
FAILED - (28.3 KB, compressed = 2.0 KB - savings of 26.3 KB) - https://reference.elasticpath.com/cortex/?zoom=navigations:element,navigations:element:child
FAILED - (6.0 KB, compressed = 2.2 KB - savings of 3.9 KB) - https://reference.elasticpath.com/
FAILED - (1.8 KB, compressed = 0.4 KB - savings of 1.4 KB) - https://reference.elasticpath.com/cortex/?zoom=lookups:navigationlookupform
FAILED - (1.8 KB, compressed = 0.4 KB - savings of 1.4 KB) - https://reference.elasticpath.com/cortex/?zoom=lookups:purchaselookupform

Google Page Speed:
Google Page Speed:
Text-based resources should be served with compression (gzip, deflate or brotli) to minimize total network bytes. Learn more.
URL
Size (KB)
Potential Savings (KB)
/vendors~app.js(reference.elasticpath.com)
552 KB
404 KB
/app.js(reference.elasticpath.com)
410 KB
347 KB
/cortex/?zoom=navigations:element,navigations:element:child(reference.elasticpath.com)
28 KB
26 KB
https://reference.elasticpath.com
6 KB
4 KB
/cortex/?zoom=lookups:navigationlookupform(reference.elasticpath.com)
2 KB
1 KB
/cortex/?zoom=lookups:purchaselookupform(reference.elasticpath.com)
2 KB
1 KB

Expected Results:
None of the above failed tests

[shaunmaharaj]

@kvanderhoek Thank you for reporting this! We had gzip compression on webpack configured but needed to re-add the same necessary capabilities for nginx.

I've added them in this PR #138.