Automatically add `deprecation_date` field to buildpack dependencies if requested

[pbusko]

Summary

Automatically populate deprecation_date for dependencies

Use Cases

This change adds the --eol-id flag to the update-buildpack-dependencies cmd. When the flag is set, the product the EOL date is looked up for a product (the --eol-id flag), formatted and added to the deprecation_date field.

Checklist

• [X] I have viewed, signed, and submitted the Contributor License Agreement.
• [X] I have linked issue(s) that this PR should close using keywords or the Github UI (See docs)
• [X] I have added an integration test, if necessary.
• [X] I have reviewed the styleguide for guidance on my code quality.
• [X] I'm happy with the commit history on this PR (I have rebased/squashed as needed).

[dmikusa]

I don't feel like we should pull in a dependency on github.com/kobayashi/eol. It's a 0.1.0 release and hasn't been updated in over a year (last commit). It doesn't show strong signs of life. If I'm missing something there please let me know.

It may be a little more work, but there are only three API calls for the API itself, https://endoflife.date/docs/api. Do you have any objections to just making HTTP calls directly to the API? You could add a client under the internal package, so we don't need to worry about exporting that as public, it'll be just for the library.

Aside from that, 👍 I like the idea. Automating metadata information is great.

[pbusko]

It's a 0.1.0 release and hasn't been updated in over a year (last commit)

good point, I've moved the implementation to the internal package

[c0d1ngm0nk3y]

@dmikusa We call the API directly instead of using the additional dependency like you proposed in this comment. Maybe you can have another look.

[pbusko]

@dmikusa is there anything else blocking the PR from being merged?