feat(dashmate): allow dashmate to update minor core versions

[pshenmic]

Issue being fixed or feature implemented

Replace fixed core image version with tagged 20 core image. That enables users to update their Core without waiting for a new dashmate release once new minor release is out.

What was done?

• Replaced fixed core version with dashpay/dashd:20

How Has This Been Tested?

No

Breaking Changes

No

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated relevant unit/integration/functional/e2e tests
• I have added "!" to the title and described breaking changes in the corresponding section if my code contains any
• I have made corresponding changes to the documentation if needed

For repository code-owners and collaborators only

• I have assigned this pull request to a milestone

[shumkov]

👍

[shumkov]

👍