Migrate from Travis-CI to Github Actions

[liry]

Since Maven is not supported by Coveralls GH Action,
we also need to migrate coverage to Codecov.

[ghost]

Build succeeded (check pipeline).

[codecov-commenter]

Codecov Report

❗ No coverage uploaded for pull request base (master@bd2a1c4). Click here to learn what that means.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master     #121   +/-   ##
=========================================
  Coverage          ?   72.22%           
  Complexity        ?       42           
=========================================
  Files             ?        7           
  Lines             ?      198           
  Branches          ?       22           
=========================================
  Hits              ?      143           
  Misses            ?       47           
  Partials          ?        8           

---

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[ghost]

Build succeeded (check pipeline).

[ghost]

Build succeeded (check pipeline).

[ghost]

Build succeeded (check pipeline).

[sadam21]

LGTM

[ghost]

Build succeeded (gate pipeline).

• https://checklist.intgdc.com/job/compliance/job/gooddata-http-client-merge-compliance-check/34/ : SUCCESS in 26s
• https://checklist.intgdc.com/job/compliance/job/gooddata-http-client-fossa-scanning-zuul-el7/23/ : FAILURE in 1m 35s (non-voting)