Update Go version to 1.13 and Gosec to 2.1.0

What does this MR do?

Update Go version to 1.13 and Gosec to 2.1.0

• The rule G105 is removed from the test as it is deleted from Gosec, see this commit.

Does this MR meet the acceptance criteria?

• Changelog entry added
• Documentation created/updated for GitLab EE, if necessary
• Documentation created/updated for this project, if necessary
• Documentation reviewed by technical writer or follow-up review issue created
• Tests added for this feature/bug
• Job definition updated, if necessary
  • Auto-DevOps template
  • Job definition example
  • CI Templates
• Conforms to the code review guidelines
• Conforms to the Go guidelines
• Security reports checked/validated by reviewer