Update Typescript version

[carloslfu]

Spread operator is supported in recent versions and is not supported in webpackbin.com

[christianalfoni]

@carloslfu There is a problem with latest TypeScript version, related to this: microsoft/TypeScript#11834

I tried awesome-typescript-loader, but that gave other issues related to running "in-memory". Hoping someone will create a PR to ts-loader project as it seems solvable, just not getting attention.