"tweak docker develop" fails if docker group doesn't exist

[msrb]

It looks like docker support in DevAssistant is tied to existence of "docker" group. This group doesn't exist in some distributions (e.g. Fedora 22). More importantly, the recommendation seems to be to use "sudo" instead.

We should probably rethink how we want to interact with docker daemon.

(stack trace from DA in F22, i.e. v0.11.2)

Traceback (most recent call last):
  File "/usr/bin/da", line 9, in <module>
    load_entry_point('devassistant==0.11.2', 'console_scripts', 'da')()
  File "/usr/lib/python3.4/site-packages/devassistant/cli/cli_runner.py", line 78, in run
    to_run.run()
  File "/usr/lib/python3.4/site-packages/devassistant/path_runner.py", line 55, in run
    self._run_path_run('', self.parsed_args)
  File "/usr/lib/python3.4/site-packages/devassistant/path_runner.py", line 33, in _run_path_run
    self.path[-1].run(stage, parsed_args)
  File "/usr/lib/python3.4/site-packages/devassistant/yaml_assistant.py", line 30, in inner
    return method(self, *args, **kwargs)
  File "/usr/lib/python3.4/site-packages/devassistant/yaml_assistant.py", line 251, in run
    return lang.run_section(getattr(self, to_run, {}), kwargs, runner=self)
  File "/usr/lib/python3.4/site-packages/devassistant/lang.py", line 145, in run_section
    return eval_exec_section(section, kwargs, runner)
  File "/usr/lib/python3.4/site-packages/devassistant/lang.py", line 167, in eval_exec_section
    retval = run_section(to_run, kwargs, runner=runner)
  File "/usr/lib/python3.4/site-packages/devassistant/lang.py", line 145, in run_section
    return eval_exec_section(section, kwargs, runner)
  File "/usr/lib/python3.4/site-packages/devassistant/lang.py", line 187, in eval_exec_section
    comm_ret = eval_exec_section(comm, kwargs, runner)
  File "/usr/lib/python3.4/site-packages/devassistant/lang.py", line 202, in eval_exec_section
    retval = Command(comm_type, comm, kwargs=kwargs).run()
  File "/usr/lib/python3.4/site-packages/devassistant/lang.py", line 60, in run
    return cr(self).run()
  File "/usr/lib/python3.4/site-packages/devassistant/command_runners.py", line 994, in run
    self._docker_check_setup()
  File "/usr/lib/python3.4/site-packages/devassistant/command_runners.py", line 1030, in _docker_check_setup
    if not DockerHelper.user_in_docker_group(user):
  File "/usr/lib/python3.4/site-packages/devassistant/command_helpers.py", line 660, in user_in_docker_group
    return username in grp.getgrnam('docker').gr_mem
KeyError: 'getgrnam(): name not found: docker'

[tradej]

Truth be told, we shouldn't use the docker group at all (as described in this or this blog post).