Pass LC and LANG envvars to pg_ctl calls - closes #343

[fizyk]

Chore that needs to be done:

• Add newsfragment pipenv run towncrier create [issue_number].[type].rst

Types are defined in the pyproject.toml, issue_number either from issue tracker or the Pull request number

[realDragonium]

Awesome to see this fixed so fast!

As idea for the tests mentioned in the issue:

• Create new function which calls subprocess.check_output, as argument you can give it the command it should run.
  • Make sure to returns the value of subprocess.check_output
• In the test:
  • add a special env variable to _envvars which is unlikely to be on the system by default
  • run the created function with env
  • check the return value of the function to see or it contains the special env variable