Describe the bug
Parallel client going out of scope closes connections with active output objects.

To Reproduce

Steps to reproduce the behavior:

output = ParallelClient(['localhost']).run_command('echo me') print(list(output[0].stdout)) 

Output can be truncated.

Expected behavior
Output can be read in its entirety while output objects are in scope.

Actual behaviour
Cannot read complete output.

Additional information
parallel-ssh: 2.5.3
ssh2-python: 0.22.0