Debug 'Cannot allocate memory'

Several jobs fails with [OSError] Cannot allocate memory,
but it is not clear why. Is  it caused by multiple run away process,
or just on process become fat.

Adding line to cleanup_host to save the final process list including
the memory usage.

Change-Id: Ic7455d689869092703974512d14bd121e4b44f1b
Merge "Debug 'Cannot allocate memory'"