Fixes#3494
Removes `class="next-head"` from the children of the `<Head>` component. Instead, a single sentinel meta element named `next-head-count` is appended. The content is the number of contiguous elements immediately preceding the sentinel that _would have had_ the `class="next-head"` attribute.
During an update, instead of searching for `class="next-head"`, the sentinel is located and the N previous elements are considered candidates for `oldTags`. New elements are inserted before the sentinel, and finally the sentinel is updated to reflect the new count.
* Refresh query on mount for exported pages
* Make sure to only refresh query if it is different
* Only update if search isn't empty
* Merge pre-rendered query values with
current query values
* Remove dynamic restriction for autoExporting
* Update dynamic routing test fo autoExport
* Remove autoExport from client-navigation test
* Remove logs and update trailing slash config
* Update nextExport tests in client-navigation
* Disable autoExport in export suite
Update tests to setup webdriver stuff in `jest-environment` and re-use one browser session instead of spawning one for each webdriver call to prevent creating too many BrowserStack sessions.
* Add default viewport meta tag (fixes#6698)
* Do not inject default viewport when rendering an AMP document
* Remove redundant viewport on error page
* Plumb withSideEffect() to pass through props, then use that for isAmp.
* Add tests for viewport meta tag.
* Fix linting
* Update dedupes test
* Break out client-navigation and rendering
test from basic test
* Try with parallelism dialed back to 3
* Update jest-junit for more compatible timings in CircleCI
* Bump to test timings
* Use filepath for suitename in jest-junit
* Store reports as artifacts
* Try using classname for timings
* Bump
* Remove reports from artifacts
