Add a lint rule to catch incorrect imports

[rnewman]

It's possible for something like

import '../../src/foo/bar';

to build just fine, but it generates incorrect .d.ts files. We should add a lint rule like

https://github.com/benmosher/eslint-plugin-import/blob/dd4e416939f83de61298610c0bee455b25063915/docs/rules/no-useless-path-segments.md

to detect this prior to landing.