ci: update codecov-action to v2

[snitin315]

This PR contains a:

• bugfix
• new feature
• code refactor
• test update
• typo fix
• metadata update

Motivation / Use-Case

update codecov-action to v2 in workflow

Breaking Changes

None

Additional Info

No

[codecov]

Codecov Report

Merging #115 (8c788f7) into master (8b3450a) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #115   +/-   ##
=======================================
  Coverage   98.46%   98.46%           
=======================================
  Files           8        8           
  Lines         261      261           
  Branches       77       77           
=======================================
  Hits          257      257           
  Misses          3        3           
  Partials        1        1           

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