chore(deps): update actions/checkout action to v2

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
actions/checkout	action	patch	v2 # required to compare -> v2

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[codecov]

Codecov Report

Merging #52 (a2a0c1d) into master (7b0079b) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master      #52   +/-   ##
=========================================
  Coverage     27.53%   27.53%           
  Complexity       57       57           
=========================================
  Files            41       41           
  Lines          1017     1017           
  Branches         85       85           
=========================================
  Hits            280      280           
  Misses          734      734           
  Partials          3        3           

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