Ruby 2.5 support

[okeefm]

This PR updates Health Data Standards to support Ruby 2.5, to get Bonnie/Cypress off of End-of-Life'd versions of Ruby. It also includes some CCDA export fixes, which are less important, but were a part of the branch when it came from Jay Walonoski and the Synthea team. It can be removed as needed.

Pull requests into Health Data Standards require the following. Submitter and reviewer should :white_check_mark: when done. For items that are not-applicable, note it's not-applicable ("N/A") and :white_check_mark:.

Submitter:

• [x] This pull request describes why these changes were made.
• [x] This PR is into the correct branch.
• [x] Internal ticket for this PR: N/A
• [x] Internal ticket links back to this PR N/A
• [ ] Code diff has been done and been reviewed (it does not contain: additional white space, not applicable code changes, debug statements, etc.)
• [x] Tests are included and test edge cases
• [x] Tests have been run locally and pass
• [ ] Code coverage has not gone down and all code touched or added is covered.
  • In rare situations, this may not be possible or applicable to a PR. In those situations:
    1. Note why this could not be done or is not applicable here:
    2. Add TODOs in the code noting that it requires a test
    3. Add a JIRA task to add the test and link it here:

Cypress Reviewer:

Name:

• [ ] Code is maintainable and reusable, reuses existing code and infrastructure where appropriate, and accomplishes the task’s purpose
• [ ] The tests appropriately test the new code, including edge cases
• [ ] You have tried to break the code

Bonnie Reviewer:

Name:

• [ ] Code is maintainable and reusable, reuses existing code and infrastructure where appropriate, and accomplishes the task’s purpose
• [ ] The tests appropriately test the new code, including edge cases
• [ ] You have tried to break the code