def run_shell(command, fail_message=nil)
      strout, status = Open3.capture2e command
      raise strout if status.to_i != 0
      return strout
    rescue Exception => ex
      fail_message ||= "Failed to run the command: #{command}"
      raise Siba::Error, "#{fail_message}
#{ex.message}"
    end
def run_shell(command, fail_message=nil)
      strout, status = Open3.capture2e command
      raise strout if status.to_i != 0
      return strout
    rescue Exception => ex
      fail_message ||= "Failed to run the command: #{command}"
      raise Siba::Error, "#{fail_message}
#{ex.message}"
    end
Runs shell command and raises error if it fails
 returns output (both stdout and stderr)