Issue

• Invoking rhevm-shell commands from non-interactive shell gives error as OSError: [Errno 6] No such device or address: '/dev/tty'. When invoked from shell gives the proper results in the file.

# cat /tmp/rhevm-shell.output
Traceback (most recent call last):
  File "/usr/bin/rhevm-shell", line 9, in <module>
    load_entry_point('rhevm-shell==3.2.0.9-SNAPSHOT', 'console_scripts', 'rhevm-shell')()
  File "/usr/lib/python2.6/site-packages/ovirtcli/main.py", line 27, in main
    context = OvirtCliExecutionContext(sys.argv, parser)
  File "/usr/lib/python2.6/site-packages/ovirtcli/context.py", line 45, in __init__
    super(OvirtCliExecutionContext, self).__init__(args=args, option_parser=option_parser)
  File "/usr/lib/python2.6/site-packages/cli/context.py", line 71, in __init__
    self.terminal = create(self.Terminal)
  File "/usr/lib/python2.6/site-packages/cli/object.py", line 26, in create
    obj = cls(sys.stdin, sys.stdout, sys.stderr, **kwargs)
  File "/usr/lib/python2.6/site-packages/cli/platform/posix/terminal.py", line 36, in __init__
    self._tty = os.open('/dev/tty', os.O_RDWR)
OSError: [Errno 6] No such device or address: '/dev/tty'