Add integration tests for genesis initialization and export

[defihyung]

Description

This PR closes: #191 and it adds build and test-race jobs in github action workflow.

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• 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
• Review Codecov Report in the comment section below once CI passes

[codecov]

Codecov Report

Merging #223 (31d8f20) into develop (45cacb8) will increase coverage by 0.09%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           develop     #223      +/-   ##
===========================================
+ Coverage    82.84%   82.93%   +0.09%     
===========================================
  Files           20       20              
  Lines         2215     2215              
===========================================
+ Hits          1835     1837       +2     
+ Misses         209      208       -1     
+ Partials       171      170       -1     

Impacted Files	Coverage Δ
x/liquidity/keeper/genesis.go	90.47% <0.00%> (+9.52%)	⬆️

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