Bump semver in /packages/eslint-config-fbjs-opensource (#511)

Bumps [semver](https://github.com/npm/node-semver) from 6.3.0 to 6.3.1.
- [Release notes](https://github.com/npm/node-semver/releases)
- [Changelog](https://github.com/npm/node-semver/blob/v6.3.1/CHANGELOG.md)
- [Commits](npm/node-semver@v6.3.0...v6.3.1)

---
updated-dependencies:
- dependency-name: semver
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

packages/eslint-config-fbjs-opensource/yarn.lock

@@ -509,8 +509,9 @@ resolve@^2.0.0-next.3:
     supports-preserve-symlinks-flag "^1.0.0"
 
 semver@^6.3.0:
-  version "6.3.0"
-  resolved "https://registry.yarnpkg.com/semver/-/semver-6.3.0.tgz#ee0a64c8af5e8ceea67687b133761e1becbd1d3d"
+  version "6.3.1"
+  resolved "https://registry.yarnpkg.com/semver/-/semver-6.3.1.tgz#556d2ef8689146e46dcea4bfdd095f3434dffcb4"
+  integrity sha512-BR7VvDCVHO+q2xBEWskxS6DJE1qRnb7DxzUrogb71CWoSficBxYsiAGd+Kl0mmq/MprG9yArRkyrQxTO6XjMzA==
 
 side-channel@^1.0.4:
   version "1.0.4"