Bump json from 20200518 to 20210307 in /fhir-parent

Bumps [json](https://github.com/douglascrockford/JSON-java) from 20200518 to 20210307.
- [Release notes](https://github.com/douglascrockford/JSON-java/releases)
- [Changelog](https://github.com/stleary/JSON-java/blob/master/docs/RELEASES.md)
- [Commits](https://github.com/douglascrockford/JSON-java/commits)

---
updated-dependencies:
- dependency-name: org.json:json
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

fhir-parent/pom.xml

@@ -208,7 +208,7 @@
             <dependency>
                 <groupId>org.json</groupId>
                 <artifactId>json</artifactId>
-                <version>20200518</version>
+                <version>20210307</version>
                 <scope>test</scope>
             </dependency>
             <dependency>