Update examples with-relay-modern and with-relay-modern-server-express to react-relay 2.0.0

- react-relay has started to use new Context API instead of Legacy Context API
- add `parseInt` because graphql 14.0.0 introduced stricter scalar value coercion

Closes #6157

This reverts the changes made in [this pr](https://github.com/zeit/next.js/pull/6109).
`redux-saga: "1.0.0"` changed the way it handles it's queues. Because of that we're still having trouble to implement the synchronous side-effects flow in `next-redux-saga`. See [this discussion](https://github.com/bbortt/next-redux-saga/pull/1) for more information.
Therefore I would feel more comfortable not to mislead users by giving them a non-working example in the main branch.

* Update README.md

I know I'm a moron for not understanding what's written in black on white, but... Maybe this will save someone an hour or two 😄

* Apply proposed changed

Updated README.md with proper link to 'root-static-files' example.

Fixes https://github.com/zeit/next.js/issues/6138

Tested with both latest and 8.0.0-canary.17

Fixes #6144 

I tried to make the example a bit more descriptive. I changed `publicPath` in `now.config.js` to be `/_next/static/`, in place of `./`, and `outputPath` to `static/` in place of `static/css/`.  The reason is that the webpack config will still fallback to `file-loader` for any content that is imported by the user and which is bigger that `8192` bytes. I think this content should not land in the css folder, which should probably stay css specific.

Moreover, for user content, like regular images, the former settings will fail.

If you have this:

```javascript
import LargeFile from './LargeFile.png'
```

it would be placed in `static/css/` but its url would resolve to `<base-url>/LargeFile.png`, which will fail. It works for semantic-ui alone, because `@zeit/next-css` will put the styles in `static/css/` and so `publicPath` of `./` would work just fine.

Putting assets in `static/` and setting `publicPath` to '/_next/static/' will resolve correctly for both semantic-ui related assets as well as for regular user assets.

I hope I am not mixing something up. I tested it locally and in serverless deployment, and this looks pretty consistent.

* Implement circular JSON err.sh link

* Add test for getInitialProps returning circular json

* Make test warn less

* Fix tests

* Add reference to original tests

Fixes #6140

This reverts commit 9112f63e.

Hi there
I noticed you have not yet included the api breaking changes in `"redux-saga": "1.0.0"`. Therefore I felt free to upgrade the dependencies in `examples/with-redux-saga`.
I do not know anything about apollo nor graphql, that is why I did not upgrade `examples/with-apollo-and-redux-saga`. But, I think you should do this on occasion.
Keep the great work up.
Regards

* show pages created when building

* fix types

Fixes #6117

I'm not entirely sure why we had this rule in the first place. I think for some tests related things when we didn't have a monorepo yet. However it could also be related to bundle sizes. I'll compare that when the build finishes.

The reason for #6117 is that we added `react-is` to the dependency tree of Next.js to check valid elements. react-redux uses hoist-non-react-statics which ships a different version of react-is in this case, one that has `ReactIs.isMemo`

Solves a bunch of inconsistencies in handling React elements too.

Start at making side-effect.js / head.js smaller.

Fixes #6121

We want our new memory optimizations (https://github.com/webpack/webpack/pull/8609)

I've updated the TypeScript dependency to the latest version. Also
removed some dependencies that may not be needed.

I've also fixed tslint errors which may have appeared because of
previous updates to this starter kit, as well as added comments
to explain some parts of the code.

I was noticing some bad memory leak on my company's application and I ended up finding this github issue ( https://github.com/styled-components/styled-components/issues/1624 ) .

This comment ( https://github.com/styled-components/styled-components/issues/1624#issuecomment-425382979 ) caught my attention, which lead to this other issue on the repository of styled components website ( https://github.com/styled-components/styled-components-website/issues/329 )

After applying the changes on my project I noticed a huge improvement on memory consumption.

So would be nice to update the example or start a discussion on how to solve this properly 

* Move phases back to next/constants

* Fix typescript error

The current `examples/with-typescript` is not using the latest type definitions currently available on DefinitelyTyped project for next.

Added new list page examples that demonstrate how to use the new Types for both stateless functional components and classes.  Also modified examples for list to demonstrate typings for `getInitialProps`.

Fixes #5363

I noticed this happening when making some changes on the nextjs.org/learn app. Basically we didn't apply updates when a warning was emitted from webpack. This would cause issues for users using eslint-loader or similar too.