R4R: Upgrade to go 1.11.5

[alessio]

Rationale: fixes upstream issue golang/go#29903

• Linked to github-issue with discussion and accepted design OR link to spec that describes this work.
• Wrote tests
• Updated relevant documentation (docs/)
• Added entries in PENDING.md with issue #
• 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 #3464 into develop will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff            @@
##           develop    #3464   +/-   ##
========================================
  Coverage    59.47%   59.47%           
========================================
  Files          135      135           
  Lines         9981     9981           
========================================
  Hits          5936     5936           
  Misses        3673     3673           
  Partials       372      372

[cwgoes]

I think there are some scripts and docs which also need to be updated, search for 1.11.4 - and also PENDING.md.

[alessio]

@cwgoes done