title: Execute command usage fails
body: <pre><code>*** Settings ***
  
      Documentation      Transfer a file from OCU to PC
      Library            SSHLibrary
      Suite Setup        Open Connection and Login With Public Key
      Suite Teardown     Close All Connections
  
  *** Variables ***
  
      ${REMOTE HOST}    192.168.x.xxx
      ${USER}           xxx
  
  *** Keywords ***
  
      Open Connection and Login With Public Key
  
      Open Connection     ${REMOTE HOST} 
      Login With Public Key     ${USER}     /home/bhushan/.ssh/id_rsa
  
  *** Test Cases ***
  
  
      Run the given command on the console
  
      ${pwd}= Execute Command     pwd
  
      Should Be Equal     ${pwd}      /home/root 
  
      ${output}=  Execute Command     ls
  
      ${output}=  Execute Command        scp /home/root/myfile.txt bhushan@192.168.x.xxx:/home/bhushan/vdr-reports/
      Log ${output} 
  </code></pre>
  
  <p>I have Dropbear of the latest version installed on my target. I am trying to run the above SSH Library Robot framework keyword based test case which defines to transfer a file from remote to the local host. The execute command keyword works in the beginning i.e. ${output}=   Execute Command     ls, but i am getting an error while using the same keyword in copying the files, i.e i can't see anything happening on the console. It is hanging and i waited for long time to see the output but haven't seen anything. But this works when i copy the files to my local machine manually. Can anyone here try to help me in fixing this error.</p>
  
  <blockquote>
    <p>KEYWORD ${output} = SSHLibrary . Execute Command scp
    /home/root/myfile.txt bhushan@192.168.x.xxx:/home/bhushan/vdr-reports/
    Documentation:     Executes <code>command</code> on the remote machine and returns
    its outputs. Start / End / Elapsed:   20170829 10:26:23.897 / 20170829
    10:26:50.148 / 00:00:26.251 10:26:23.898  INFO    Executing command 'scp
    /home/root/myfile.txt
    bhushan@192.168.x.xxx:/home/bhushan/vdr-reports/'...................></p>
  </blockquote>
  
  <p>This is what i see in the log</p>