Crash when saving settings without a config dir

[amanusk]

Step 1: Describe your environment

• System (Intel/AMD/Raspberry Pi etc): Raspberry Pi
• OS version: Raspbian-stresh
• s-tui version: 0.8.2
• Installation method(pip/PPA/source code): source code

Step 2: Describe the problem:

Observed Results:

Crash when trying to save settings and no .config dir exists

• What happened? (Traceback of a crash/Image/description):

  WARNING:root:Failed to find or create scripts directory,                             proceeding without scripting support
  Traceback (most recent call last):
  File "/usr/lib/python3.5/runpy.py", line 193, in _run_module_as_main
  "__main__", mod_spec)
  File "/usr/lib/python3.5/runpy.py", line 85, in _run_code
  exec(code, run_globals)
  File "/home/pi/s-tui/s_tui/s_tui.py", line 1001, in <module>
  main()
  File "/home/pi/s-tui/s_tui/s_tui.py", line 928, in main
  graph_controller.main()
  File "/home/pi/s-tui/s_tui/s_tui.py", line 760, in main
  self.loop.run()
  File "/usr/local/lib/python3.5/dist-packages/urwid/main_loop.py", line 286, in run
  self._run()
  File "/usr/local/lib/python3.5/dist-packages/urwid/main_loop.py", line 384, in _run
  self.event_loop.run()
  File "/usr/local/lib/python3.5/dist-packages/urwid/main_loop.py", line 788, in run
  self._loop()
  File "/usr/local/lib/python3.5/dist-packages/urwid/main_loop.py", line 825, in _loop
  self._watch_files[fd]()
  File "/usr/local/lib/python3.5/dist-packages/urwid/raw_display.py", line 404, in <lambda>
  event_loop, callback, self.get_available_raw_input())
  File "/usr/local/lib/python3.5/dist-packages/urwid/raw_display.py", line 502, in parse_input
  callback(processed, processed_codes)
  File "/usr/local/lib/python3.5/dist-packages/urwid/main_loop.py", line 411, in _update
  self.process_input(keys)
  File "/usr/local/lib/python3.5/dist-packages/urwid/main_loop.py", line 511, in process_input
  k = self._topmost_widget.keypress(self.screen_size, k)
  File "/usr/local/lib/python3.5/dist-packages/urwid/container.py", line 1590, in keypress
  key = self.focus.keypress(tsize, key)
  File "/usr/local/lib/python3.5/dist-packages/urwid/container.py", line 2271, in keypress
  key = w.keypress((mc,) + size[1:], key)
  File "/usr/local/lib/python3.5/dist-packages/urwid/decoration.py", line 622, in keypress
  return self._original_widget.keypress(maxvals, key)
  File "/usr/local/lib/python3.5/dist-packages/urwid/container.py", line 2271, in keypress
  key = w.keypress((mc,) + size[1:], key)
  File "/home/pi/s-tui/s_tui/UiElements.py", line 37, in keypress
  return super(ViListBox, self).keypress(size, key)
  File "/usr/local/lib/python3.5/dist-packages/urwid/listbox.py", line 999, in keypress
  key = focus_widget.keypress((maxcol,),key)
  File "/usr/local/lib/python3.5/dist-packages/urwid/wimp.py", line 540, in keypress
  self._emit('click')
  File "/usr/local/lib/python3.5/dist-packages/urwid/widget.py", line 460, in _emit
  signals.emit_signal(self, name, self, *args)
  File "/usr/local/lib/python3.5/dist-packages/urwid/signals.py", line 265, in emit
  result |= self._call_callback(callback, user_arg, user_args, args)
  File "/usr/local/lib/python3.5/dist-packages/urwid/signals.py", line 295, in _call_callback
  return bool(callback(*args_to_pass))
  File "/home/pi/s-tui/s_tui/s_tui.py", line 378, in save_settings
  with open(config_file, 'w') as cfgfile:
  FileNotFoundError: [Errno 2] No such file or directory: '/home/pi/.config/s-tui/s-tui.conf'

Debug Results, output of s-tui -d created in a file _s-tui.log:

* Replace this with debug output *

Step 3: Reproduce the problem:

Steps to reproduce:

1. Install Raspbian
2. Install s-tui
3. Try to use save settings