* Update tests to use fs.promises when not top-level
* Move two to asyncFilter
* Update site-data-references.js
* Update site-data-references.js
* Clear out await fs.exists
* Lint
* A few more fixes
* Can't use async when defining tests
* Revise the 'pages' module to export two methods: 'loadPages' and 'loadPageMap'
Update all existing references to use 'loadPages' for now
* Remove explicit Promise resolutions on loadPage* methods
* Condense reduction method into its now-singular usage spot
* Opt for for-of instead of forEach
* Make require of pages in warm-server more explicit
* Be more explicit about find-page using a pageMap
* Be more explicit about find-page-in-version using a pageMap
* Be more explicit about site-tree using a pageMap
* Extract the map creation from loadPageMap
* Be more explicit about using a pageMap
* Update redirects precompile to take two arguments: pageList, pageMap
* Rename internal loadPages method to loadPageList
* Clarify pageMap is what is stored in context.pages
* Use loadPageMap in tests and stuff
* remove FEATURE_NEW_VERSIONS from feature-flags.json
* remove process.env.FEATURE_NEW_VERSIONS from include files
* remove process.env.FEATURE_NEW_VERSIONS from lib files
* remove process.env.FEATURE_NEW_VERSIONS from middleware files
* remove process.env.FEATURE_NEW_VERSIONS from script files
* remove process.env.FEATURE_NEW_VERSIONS from test files
* update test fixtures to use new versions as canonical fixtures
