Always use typescript@latest for lint rules other than expect

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Currently we always use the lowest TypeScript version that a package supports when linting it. This ensures that the expect rule gets correct results. But tslint isn't compatibile with TypeScript 2.0, which causes bugs.
We should instead use typescript@latest for all other lint rules, and have expect specially use a different Program that uses an older TypeScript. (As an optimization, we should not create this if there are not // $ExpectFoo comments in the file.)