Support tags

[yyamanoi1222]

*Issue #21

Description of changes:
Add tags input

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[DmitryGulin]

Thank you very much for your PR!

I'd recommend simplifying the tag defintion format.

The current approach expects action authors to use an array of Tag compatible objects, so that the defintion would look like this:

[{ "Key": "first_tag", "The first tag value": "Tag Value" }, { "Key": "second_tag", "Value": "The second tag value" }]

The current approach is too verbose and unnecessary exposes internal dependency on AWS SDK API as a public contract.
That said, I'd suggest using a simplified version to make action defintion easier for action authors to create, understand, and support:

{ "first_tag": "The first tag value", "second_tag": "The second tag value" }

[DmitryGulin]

see my comment in the Conversation thread

[yyamanoi1222]

@DmitryGulin Thank you for your feedbacks!
I changed the format