fix(benchmarks): fix timeout errors (#457)

The use of `close` event was causing timeouts. Switching to the
`finish` event fixed it.

benchmarks/index.js

@@ -53,7 +53,7 @@ suite
  callback()
  }
  }))
- .on('close', resolve)
+ .on('finish', resolve)
  })
  }))).then(() => deferred.resolve())
  }
@@ -72,7 +72,7 @@ suite
  callback()
  }
  }))
- .on('close', resolve)
+ .on('finish', resolve)
  }))).then(() => deferred.resolve())
  }
  })
@@ -89,7 +89,7 @@ suite
  callback()
  }
  }))
- .on('close', resolve)
+ .on('finish', resolve)
  })
  }))).then(() => deferred.resolve())
  }
@@ -167,7 +167,7 @@ class SimpleRequest {
  write (chunk, encoding, callback) {
  callback()
  }
- }).on('close', resolve)
+ }).on('finish', resolve)
  }
 
  onConnect (abort) {