Add GO111MODULE=on to environment.

[yangyanqing]

• Targeted PR against correct branch (see CONTRIBUTING.md)

• Linked to github-issue with discussion and accepted design OR link to spec that describes this work.

• Wrote tests

• Updated relevant documentation (docs/)

• Added a relevant changelog entry: sdkch add [section] [stanza] [message]

• rereviewed Files changed in the github PR explorer

---

For Admin Use:

• Added appropriate labels to PR (ex. wip, ready-for-review, docs)
• Reviewers Assigned
• Squashed all commits, uses message "Merge pull request #XYZ: [title]" (coding standards)

[codecov]

Codecov Report

Merging #4042 into develop will decrease coverage by 0.01%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           develop    #4042      +/-   ##
===========================================
- Coverage    60.01%   59.99%   -0.02%     
===========================================
  Files          212      212              
  Lines        15107    15107              
===========================================
- Hits          9066     9064       -2     
- Misses        5420     5422       +2     
  Partials       621      621