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
I wrote a [script](https://github.com/j0lv3r4/dependency-version-updater) to update dependencies recursively in `package.json` files, e.g.:
```
$ node index.js --path="./examples" --dependencies="react=^16.7.0,react-dom=^16.7.0"
```
This PR contains the result against the examples folder.
* Fix with-relay-modern example
Starting with react-relay 1.5.0 the schema canno't be in the same dir as
the src. This can be fixed by excluding the schema dir. Globs should
also be inside quotation marks, to avoid non-deterministic behavior of
different shells.
* Add missing key on BlogPosts
