Update to latest typescript version

[powderham]

Currently this package is on 2.8 whereas the official npm package is at 3.3.

Our application cannot take advantage of features of other packages (e.g. styled components requires 2.9+) which is a shame.

Let me know if you need help doing this somehow.

[yorrd]

try https://atmospherejs.com/adornis/typescript, we forked and upgraded TypeScript