ignore BOM when reading ci yml file

What does this MR do?

Adds BOM ignore support for .gitlab-ci.yml file reading. Fix was based on Ruby fix recommendation from here: http://stackoverflow.com/questions/5011504/is-there-a-way-to-remove-the-bom-from-a-utf-8-encoded-file.

Are there points in the code the reviewer needs to double check?

Why was this MR needed?

workaround for when your editor (Visual Studio) keeps putting BOM on files.

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?