Increase Testing For Devfile Library

[Jdubrick]

Which area/kind this issue is related to?

/area library

Issue Description

As discussed in devfile/library#198 (comment) we should look over the test cases for Devfile Library and more specifically Test_DownloadGitRepoResources where we should add more failure tests.

Acceptance Criteria

• Reviewed test suite for devfile library to find holes
• Added more failure test cases to Test_DownloadGitRepoResources

[github-actions]

This issue is stale because it has been open for 90 days with no activity. Remove stale label or comment or this will be closed in 60 days.