Frequent test failures

Node.js runs the watchify test suite using CITGM (https://github.com/nodejs/citgm) as smoke test to identify unintended breaking changes in Node.js. We relatively frequently receive errors from watchify that seem like flakes:

https://ci.nodejs.org/view/Node.js-citgm/job/citgm-smoker/2142/nodes=osx1011/testReport/junit/(root)/citgm/watchify_v3_11_1/ (available ~7 days).

It would be great to get these fixed so that we ran rely upon the test outcome!

```
---
operator: fail
expected: 4
actual: 2
at: process. (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/index.js:88:19)
stack: |-
Error: plan != count
at Test.assert [as _assert] (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/lib/test.js:226:54)
at Test.bound [as _assert] (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/lib/test.js:78:32)
at Test.fail (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/lib/test.js:319:10)
at Test.bound [as fail] (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/lib/test.js:78:32)
at Test._exit (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/lib/test.js:183:14)
at Test.bound [as _exit] (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/lib/test.js:78:32)
at process. (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/index.js:88:19)
at process.emit (events.js:304:20)
...
not ok 14 test exited without ending
---
operator: fail
at: process. (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/index.js:88:19)
stack: |-
Error: test exited without ending
at Test.assert [as _assert] (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/lib/test.js:226:54)
at Test.bound [as _assert] (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/lib/test.js:78:32)
at Test.fail (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/lib/test.js:319:10)
at Test.bound [as fail] (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/lib/test.js:78:32)
at Test._exit (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/lib/test.js:189:14)
at Test.bound [as _exit] (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/lib/test.js:78:32)
at process. (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/index.js:88:19)
at process.emit (events.js:304:20)
...
not ok 15 test exited without ending
---
operator: fail
at: process. (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/index.js:88:19)
stack: |-
Error: test exited without ending
at Test.assert [as _assert] (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/lib/test.js:226:54)
at Test.bound [as _assert] (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/lib/test.js:78:32)
at Test.fail (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/lib/test.js:319:10)
at Test.bound [as fail] (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/lib/test.js:78:32)
at Test._exit (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/lib/test.js:189:14)
at Test.bound [as _exit] (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/lib/test.js:78:32)
at process. (/Users/iojs/tmp/citgm_tmp/823e0eb4-e0e3-4af9-a31c-2e79384be0af/watchify/node_modules/tape/index.js:88:19)
at process.emit (events.js:304:20)
...
```