PatternFly 4 version bumping

There's two steps to updating patternfly.org. The first is to update the documentation content, which upon merging to master will release to staging.patternfly.org. The second is to promote staging.patternfly.org to patternfly.org in AWS.

1. Bump versions

1. Add an entry to the packages/theme-patternfly-org/versions.json file using the recently promoted (or soon to be promoted) packages:

{
  "name": "2019.07",
  "date": "2019-09-10",
  "latest": true,
  "versions": {
    "@patternfly/patternfly": "2.31.6",
    "@patternfly/react-charts": "4.7.9",
    "@patternfly/react-core": "3.104.0",
    "@patternfly/react-styles": "3.5.22",
    "@patternfly/react-table": "2.20.15",
    "@patternfly/react-tokens": "2.6.26",
    "@patternfly/react-topology": "2.8.34",
    "@patternfly/react-icons": "3.14.2",
    "@patternfly/react-virtualized-extension": "1.2.23",
    "@patternfly/react-inline-edit-extension": "2.11.35"
  }
},

Remember to remove the line "latest": true, from the previous version.

2. Update packages/v4/package.json's "@patternfly/react-docs": "4.21.6", to the latest react-docs release. This should grab all the newly released @patternfly/* versions. Install it with yarn install. Verify that the docs are up to date using yarn start. Good sections to check are the release notes.

3. Open + merge the PR.

2. Verify staging and promote

1. Verify staging.patternfly.org works and has latest release notes. Have patternfly and patternfly-react leads verify the changes from this milestone work on the site.
2. Login to AWS and navigate to S3, open the patternfly-org-staging link & copy the entire bucket's contents to patternfly-org. Once completed, invalidate the cache in Cloudfront for our patternfly-org distribution by creating a new invalidation with simply *.
3. Verify that patternfly.org works