bump react & react-dom to 16.8

[nisarhassan12]

What it does

Fixes #7879

bumps react & react-dom to 16.8 as @akosyakov said in #7879 (comment) :

React hooks were only introduced in https://reactjs.org/blog/2019/02/06/react-v16.8.0.html but we make use them with early version in package.json. We should bump it to make sure that downstreams update their yarn.lock files.

How to test

• Start Theia things will hopefully work as they were before.
• Changelog for 16.8 https://github.com/facebook/react/blob/master/CHANGELOG.md#1680-february-6-2019 it will hopefully work fine (sorry I have not tested everything).

Review checklist

• as an author, I have thoroughly tested my changes and carefully followed the review guidelines

Reminder for reviewers

• as a reviewer, I agree to behave in accordance with the review guidelines

[vince-fugnitto]

@nisarhassan12 thank you for your contribution!

Can you please sign-off your commit (reason for the failed CI check) and also fill out the pull-request description template?

[nisarhassan12]

Thanks! @vince-fugnitto I have signed of the commit and filled the pull request description template.

[vince-fugnitto]

Thanks! @vince-fugnitto I have signed of the commit and filled the pull request description template.

I meant 'what it does' and 'how to test', we use this fields during reviews but also for traceability if we ever need to revisit the pull-request in the future.

[nisarhassan12]

@vince-fugnitto Opps Sorry.

[nisarhassan12]

@vince-fugnitto Done. Sorry for my bad communication skills.

[kittaakos]

Why not ^16.8? Is there a reason for pinning it?

[akosyakov]

@nisarhassan12 please make sure to build the project and fix compilation errors.

[vince-fugnitto]

@nisarhassan12 I see the following error:

packages/navigator/src/browser/navigator-widget.tsx:236:38 - error TS2345: Argument of type 'import("/Users/vincentfugnitto/workspace/theia/node_modules/@types/react/index").MouseEvent<HTMLElement, MouseEvent>' is not assignable to parameter of type 'React.MouseEvent<HTMLElement, MouseEvent>'.
  Type 'MouseEvent<HTMLElement, MouseEvent>' is missing the following properties from type 'MouseEvent<HTMLElement, MouseEvent>': detail, view

236         super.handleClickEvent(node, event);

[nisarhassan12]

Thanks! the project can be successfully built I have fixed the compilation errors.

[akosyakov]

@vince-fugnitto Could you test it please? Code looks good.

[vince-fugnitto]

@akosyakov sorry I didn't see the ping, I verified and did not notice any regressions 👍