enable ei integ tests

[ChoiByungWook]

Enable integ tests for elastic inference.

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• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works (if appropriate)
• I have updated the changelog with a description of my changes (if appropriate)
• I have updated any necessary documentation (if appropriate)

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[codecov-io]

Codecov Report

Merging #527 into master will not change coverage.
The diff coverage is n/a.

@@          Coverage Diff           @@
##           master    #527   +/-   ##
======================================
  Coverage    92.7%   92.7%           
======================================
  Files          71      71           
  Lines        5336    5336           
======================================
  Hits         4947    4947           
  Misses        389     389

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