Yarn 0.24.6

[XhmikosR]

@FeodorFitsner: the reason for this is some errors we get here.

[ro-savage]

Using an old version of Yarn is also causing Create React App end to end tests to crash on windows machines.

See facebook/create-react-app/pull/2400 & yarnpkg/yarn/issues/2591

[XhmikosR]

@FeodorFitsner: Will this be in the image update?

[FeodorFitsner]

@XhmikosR sure.