[BUG] permission denied for shared directory in the container when no volume was mounted

[przemyslavic]

Describe the bug
Assuming I want to run everything in the container without mounting any volume, there is an issue with permissions.
The shared directory is owned by root and therefore epicli can not write anything in it.

To Reproduce
Steps to reproduce the behavior:

1. execute docker run -it image:tag
2. execute epicli init -p aws -n xxx

Expected behavior
Configuration file has been generated and saved in the shared directory.

Additional context

Command output

epiuser@60d68dc3d233:/shared$ epicli init -p aws -n xxx
Traceback (most recent call last):
  File "/usr/local/lib/python3.7/site-packages/cli/epicli.py", line 126, in main
    return args.func(args)
  File "/usr/local/lib/python3.7/site-packages/cli/epicli.py", line 147, in run_init
    with InitEngine(args) as engine:
  File "/usr/local/lib/python3.7/site-packages/cli/engine/InitEngine.py", line 16, in __init__
    super().__init__(__name__)
  File "/usr/local/lib/python3.7/site-packages/cli/helpers/Step.py", line 8, in __init__
    self.logger = Log(step_name)
  File "/usr/local/lib/python3.7/site-packages/cli/helpers/Log.py", line 33, in __new__
    Log.instance = Log.__LogBase()
  File "/usr/local/lib/python3.7/site-packages/cli/helpers/Log.py", line 17, in __init__
    log_path = os.path.join(get_output_path(), config.log_file)
  File "/usr/local/lib/python3.7/site-packages/cli/helpers/build_saver.py", line 76, in get_output_path
    os.makedirs(Config().output_dir)
  File "/usr/local/lib/python3.7/os.py", line 223, in makedirs
    mkdir(name, mode)
PermissionError: [Errno 13] Permission denied: '/shared/build/'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/local/bin/epicli", line 8, in <module>
    sys.exit(main())
  File "/usr/local/lib/python3.7/site-packages/cli/epicli.py", line 128, in main
    logger = Log('epicli')
  File "/usr/local/lib/python3.7/site-packages/cli/helpers/Log.py", line 33, in __new__
    Log.instance = Log.__LogBase()
  File "/usr/local/lib/python3.7/site-packages/cli/helpers/Log.py", line 17, in __init__
    log_path = os.path.join(get_output_path(), config.log_file)
  File "/usr/local/lib/python3.7/site-packages/cli/helpers/build_saver.py", line 76, in get_output_path
    os.makedirs(Config().output_dir)
  File "/usr/local/lib/python3.7/os.py", line 223, in makedirs
    mkdir(name, mode)
PermissionError: [Errno 13] Permission denied: '/shared/build/'

drwxr-xr-x 2 root root 4096 Jun 18 12:54 shared