Isomorphic unfetch is failing at runtime server side, window not defined

[eric-burel]

developit/unfetch#104
developit/unfetch#122

We should either improve the typeScript/webpack build process.
Switching to cross-fetch does not work, as unfetch is probably also a dependency of a subpackage.

We might need to define window as global variable, set to undefined, in webpack.

[developit]

FWIW the only way you'd be seeing window is if the build system here (I'm not familiar with it) is incorrectly following isomorphic-unfetch's "browser" package.json mainField.

[eric-burel]

Yeah the build was messy, I was bundling the full node_modules with webpack. I think now it works correctly but our build system is not yet mature.