EOF error in `TestNewClient`

[nkryuchkov]

Describe the bug
During the implementation of skycoin/dmsg#2 TravisCI failed with EOF error in TestNewClient in a21feaa commit.

This is a floating bug. After failed TravisCI build, I was unable to reproduce the bug.

Environment information:

• TravisCI

Steps to Reproduce
Steps to reproduce the behavior:

1. Run TravisCI build

Actual behavior
TestNewClient fails with EOF error (panic is raised by test itself).

Expected behavior
TestNewClient passes.

Additional context
Failed TravisCI build link:
https://travis-ci.com/skycoin/dmsg/builds/117521843

Possible implementation
For the commit skycoin/dmsg@a21feaa the lines where the error may occur are between 811 and 817.