Validate FHIR Resources before publishing.

[lincmba]

fixes https://github.com/onaio/fhir-tooling/issues/87

IMPORTANT: Where possible all PRs must be linked to a Github issue

Fixes #[issue number] or Closes #[issue number]

Engineer Checklist

• [x] I have run ./gradlew spotlessApply to check my code follows the project's style guide
• [x] I have built and run the efsity jar to verify my change fixes the issue and/or does not break the application

[pld]

do these tests cover this pr? https://github.com/onaio/fhir-tooling/pull/100