Update to forked sdk v0.38.2, with restart bugfix

[ethanfrey]

Closes #54

While waiting for upstream fix, use confio fork, that takes in the upstream fix to the iavl/restart issue and a few minor debugging enhancements I came across.

• 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 relevant godoc comments.

• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md

• Re-reviewed Files changed in the Github PR explorer

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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-io]

Codecov Report

Merging #66 into master will increase coverage by 0.06%.
The diff coverage is 100%.

@@            Coverage Diff            @@
##           master     #66      +/-   ##
=========================================
+ Coverage   63.44%   63.5%   +0.06%     
=========================================
  Files          14      14              
  Lines        1116    1118       +2     
=========================================
+ Hits          708     710       +2     
  Misses        341     341              
  Partials       67      67

Impacted Files	Coverage Δ
app/app.go	89.09% <100%> (+0.13%)	⬆️

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