Add test for resource JSON marshaling - ActionVariable

[ResamVi]

Hello,

this is just another trivial test adding to the 10 year old issue. I hope there is still demand for this.

Helps #55

[gmlewis]

Thank you, @ResamVi - is this for hacktoberfest credit?
If so, I'll label it as accepted.

[gmlewis]

Please make sure unit tests pass locally first by running go test ./....

[codecov]

Codecov Report

Merging #2942 (73ea7e5) into master (d99d3df) will not change coverage.
The diff coverage is n/a.

@@ Coverage Diff @@## master #2942 +/- ##
=======================================
Coverage 98.19% 98.19% =======================================
Files 145 145 Lines 12720 12720 =======================================
Hits 12490 12490 Misses 156 156 Partials 74 74 

[ResamVi]

Whoops, that was a tad too hasty of me 🙈 . Should be fixed now.

This is indeed for hacktoberfest so I would happily take the accept label :). Thanks for your time!

[gmlewis]

Thank you, @ResamVi !
LGTM.
Merging.