Add tags to ECS tasks

[nickhurlburt]

Goal

I want to be able to track our AWS spend by environment (eg prod/staging/dev). This is easy to do when our AWS resources all have an Environment tag.

One of our major costs is our running ECS tasks for HRM and the job processor. For some weird reason, it seems that in order to divide costs, the tasks themselves need to be tagged. Tagging the clusters or services is insufficient.

I have manually added a tag here and it seems to be tracking costs as desired.

This draft PR is my attempt to have these tags created as part of our automated deploys. I could use a little help from someone in seeing if this is correct and testing it out.

Checklist

• Corresponding issue has been opened
• [n/a] New tests added
• [n/a] Feature flags / configuration added

Verification steps

• After a deploy, check that the ECS tasks for HRM and the job processor have the appropriate tags.
• After a couple days, look at the billing and cost explorer in AWS to confirm that ECS charges are correctly categorized.

AFTER YOU MERGE

1. Cut a release tag using the GitHub workflow. Wait for it to complete and notify in the #aselo-deploys Slack channel.
2. Comment on the ticket with the release tag version AND any additional instructions required to configure an environment to test the changes.
3. Only then move the ticket into the QA column in JIRA

You are responsible for ensuring the above steps are completed. If you move a ticket into QA without advising what version to test, the QA team will assume the latest tag has the changes. If it does not, the following confusion is on you! :-P