upgrade module support

[fedekunze]

Description

• Adds support for the upgrade module for managing software updates.
• Add additional baseapp options to the application

---

For contributor use:

• 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.
• Code follows the module structure standards.
• Wrote unit and integration tests
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Added relevant godoc comments.
• 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, R4R, docs, etc)
• Reviewers assigned
• Squashed all commits, uses message "Merge pull request #XYZ: [title]" (coding standards)

[codecov]

Codecov Report

Merging #471 into development will increase coverage by 0.02%.
The diff coverage is 83.33%.

@@               Coverage Diff               @@
##           development     #471      +/-   ##
===============================================
+ Coverage        69.92%   69.94%   +0.02%     
===============================================
  Files               38       38              
  Lines             2487     2489       +2     
===============================================
+ Hits              1739     1741       +2     
  Misses             617      617              
  Partials           131      131              

Impacted Files	Coverage Δ
app/test_helpers.go	0.00% <0.00%> (ø)
app/ethermint.go	88.09% <100.00%> (+0.14%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update b3c895d...f1cb343. Read the comment docs.