fix(deps): Upgrade connect 3.

[dignifiedquire]

This means dropping support for node 0.8.

This is pretty much working but the tests are broken as the outdated mocks library is not handling the req.resume and req.pause methods properly.

Found a good replacement https://github.com/WhoopInc/supertest-as-promised and refactored all the failing tests. We should plan to move all the other tests for middleware to it as well, as it is much more reliable.

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Ref #1410

[dignifiedquire]

@maksimr could you review this please?

[maksimr]

LGTM

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[dignifiedquire]

Merged into canary as d585032