Issue #29: Use the correct operator for concatenating arrays of tags.

[Castaglia]

Pull Request Checklist

Is this in reference to an existing issue?

General

• [x] Update Changelog following the conventions laid out here

• [ ] Update README with any necessary configuration snippets

• [ ] Binstubs are created if needed

• [x] RuboCop passes

• [x] Existing tests pass

New Plugins

• [ ] Tests

• [ ] Add the plugin to the README

• [ ] Does it have a complete header as outlined here

Purpose

Known Compatibility Issues

[luisdavim]

Hi, thanks for your contribution. Could you by any chance also take a look at the failing tests?

[Castaglia]

@luisdavim Build fixed. Thanks!

[majormoses]

released: https://rubygems.org/gems/sensu-plugins-opsgenie/versions/4.1.2