Config File Error The config file you specified doesn't seem to be a .yml file.

• Atom version: 1.22.1 x64
• linter-sass-lint version: 1.8.3
• Global sass-lint version (if used):
• Platform:
  • OSX
  • Windows
  • Linux
• Expected behaviour: No error message
• Actual behaviour / issue description:
  When running sass-lint with a scss-file, it shows me all errors and hints to improve my sass-syntax, but I constantly get the message "Config File Error The config file you specified doesn't seem to be a .yml file. Please see the sass-lint documentation on how to create a config file."
  I tried both the files from https://github.com/sasstools/sass-lint/blob/master/lib/config/sass-lint.yml and https://github.com/sasstools/sass-lint/blob/master/docs/sass-lint.yml
  I put the sass-lint.yml in the custom theme folder of my drupal project, so the folder structure is:
  themename/sass-lint.yml
  themename/sass/style.scss
  They are valid yaml files according to online yaml linters, but sass-lint always shows me the error message above every time I change something in a scss-file.