[7.8] go es

[simitt]

Motivation/summary

Update the go-elasticsearch dependency to the 7.8 branch.

Checklist

- [ ] I have signed the Contributor License Agreement.
- [ ] I have updated CHANGELOG.asciidoc

I have considered changes for:

• documentation
• logging (add log lines, choose appropriate log selector, etc.)
• metrics and monitoring (create issue for Kibana team to add metrics to visualizations, e.g. Kibana#44001)
• automated tests (add tests for the code changes, all unit tests pass locally)
• telemetry
• Elasticsearch Service (https://cloud.elastic.co)
• Elastic Cloud Enterprise (https://www.elastic.co/products/ece)
• Elastic Cloud on Kubernetes (https://www.elastic.co/elastic-cloud-kubernetes)

How to test these changes

make test

[apmmachine]

💚 Build Succeeded

Expand to view the summary

Build stats

• Build Cause: [Branch indexing]

• Start Time: 2020-05-12T11:49:58.333+0000

• Duration: 28 min 36 sec (1655917)

Test stats 🧪

Test	Results
Failed	0
Passed	3008
Skipped	142
Total	3150

[simitt]

failing docs test seems unrelated

[codecov-io]

Codecov Report

Merging #3780 into 7.8 will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##              7.8    #3780   +/-   ##
=======================================
  Coverage   79.81%   79.81%           
=======================================
  Files         136      136           
  Lines        6152     6152           
=======================================
  Hits         4910     4910           
  Misses       1242     1242           

[axw]

Confirmed with ngrep -q "go-elasticsearch", running apm-server apikey info --name=foo triggering a query:

GET /_security/api_key?name=foo HTTP/1.1..Host: elasticsearch:9200..User-Agent: go-elasticsearch
/7.8.0 (linux amd64; Go 1.13.9)..Authorization: Basic YWRtaW46Y2hhbmdlbWU=..Accept- 
Encoding: gzip....