Add support to pass build meta_data in trigger steps

[iaroslav-ciupin]

Synopsis

Buildkite supports passing meta_data in trigger step. Looks like this functionality was missing.

Resolves #133

[iaroslav-ciupin]

@adikari Thanks for review/approve! Not sure if CI failure is related to my change. Can you please take a look why is it failing?

[adikari]

It would be related to your change. I will have a look and update it as soon as I can.

[iaroslav-ciupin]

@adikari please let me know what should I do to fix the CI failures

[adikari]

@iaroslav-ciupin there are tests for bash scripts that are failing. You might have to update the best for it to pass. If you want to fix it, I think there are some instructions on contributing guidance on how to do it (I am guessing).
I will look into it this morning but feel free to have a crack.

[adikari]

It looks like in the new buildkite/plugin-tester path to the /load.bash has changed hence the tests were failing. I have updated it appropriately. Hopefully it will fix it

[adikari]

@iaroslav-ciupin I had to fix a bunch of things related to the tests. To speed up things I have created another PR #134 based on your changes. I will close this PR in favour of that. Will get it released soon. Thanks for contributing.