Projector uses `Array.prototype#find`, which is unavailable in IE10/IE11

[JC Franco]

Running maquette on IE10/IE11 will sometimes throw the following error:

Object doesn't support property or method 'find'

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Based on the Browser support page:

Polyfills

All evergreen browsers (Edge, Chrome and Firefox) do not require polyfills,
as do IE10 and IE11.

projector.ts needs to avoid using Array.prototype#find.

[Johan Gorter]

Thanks for pointing this out, fix is underway