fails test with latest end-of-stream

[ronag]

I don't exactly understand how mafintosh/end-of-stream@c023407 can cause the failure. But the failure seems related to two things:

• error/close is emitted asynchronously from destroy which causes unpipe to be delayed resulting in a write after destroy (stream: pipe and async error nodejs/node#29790)
• error can be emitted twice (this I believe has been fixed in Node master so it might be worth to just wait for a stream-readable update). The second error should just be swallowed. However, the problem here is that the write after destroy error might be preceded by the actual error (see comment in stream: pipe and async error nodejs/node#29790)

Ref: nodejs/node#29504

# preserves error again
ok 19 should be truthy
ok 20 does not close with premature close
ok 21 should be truthy
ok 22 does not close with premature close
not ok 23 .end() called twice
  ---
    operator: fail
    at: Pumpify.<anonymous> (/Users/ronagy/GitHub/public/pumpify/test.js:210:9)
    stack: |-
      Error: .end() called twice
          at Test.assert [as _assert] (/Users/ronagy/GitHub/public/pumpify/node_modules/tape/lib/test.js:225:54)
          at Test.bound [as _assert] (/Users/ronagy/GitHub/public/pumpify/node_modules/tape/lib/test.js:77:32)
          at Test.fail (/Users/ronagy/GitHub/public/pumpify/node_modules/tape/lib/test.js:318:10)
          at Test.bound [as fail] (/Users/ronagy/GitHub/public/pumpify/node_modules/tape/lib/test.js:77:32)
          at Test.end (/Users/ronagy/GitHub/public/pumpify/node_modules/tape/lib/test.js:151:14)
          at Test.bound [as end] (/Users/ronagy/GitHub/public/pumpify/node_modules/tape/lib/test.js:77:32)
          at Pumpify.<anonymous> (/Users/ronagy/GitHub/public/pumpify/test.js:210:9)
          at Pumpify.emit (events.js:209:13)
          at Pumpify.Duplexify._destroy (/Users/ronagy/GitHub/public/pumpify/node_modules/duplexify/index.js:195:15)
          at /Users/ronagy/GitHub/public/pumpify/node_modules/duplexify/index.js:185:10
  ...