Migration Testing

[alexanderbez]

• Add TODO to return error in migration command instead of panic
• Fix version in x/staking (v0.37 to v0.38)
• Update v0.38 migration to include staking

---

• 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 to the Unreleased section in CHANGELOG.md

• Re-reviewed 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 #5103 into master will increase coverage by 0.05%.
The diff coverage is 75%.

@@            Coverage Diff             @@
##           master    #5103      +/-   ##
==========================================
+ Coverage    54.8%   54.85%   +0.05%     
==========================================
  Files         294      295       +1     
  Lines       18222    18261      +39     
==========================================
+ Hits         9986    10017      +31     
- Misses       7490     7495       +5     
- Partials      746      749       +3