Added two tests for issue #1449 - however both are passing at the unit level so
I suspect that the issue will need to be tested at the integration test level.
Add integration test for issue #1449.
Fix issue #1449 by collecting the prefix_header_contents and uniq-ing them.
fix #1042 - keep absolute paths for local pods as is
try to get test wrapped around absolute path
Addressed comments from @irrationalfab:
- simplified collection of unique prefix_header_contents
- reduced sub specs in spec from 4 to 2
Removed inline documentation and added @notes and @todos.
Added entry to Changelog.
remove "was_absolute" tracking and simplify local pod handling to always use absolute paths
working spec for abs root
return Pathname instead of string, remove obsolete comment
preserve local pod paths specified as absolute or rooted to home
clean up naming a little bit absolute path tracking
[linter] Validate screenshots are valid

Closes #2010
[linter] Exclude screenshot validation from other tests
[linter] Validate screenshot URLs return a valid image
Merge pull request #2016 from CocoaPods/screenshots

[linter] Validate screenshots are valid
Merge branch 'issue_1449_duplicate_prefix_header_contents' of https://github.com/luisdelarosa/CocoaPods into luisdelarosa-issue_1449_duplicate_prefix_header_contents

* 'issue_1449_duplicate_prefix_header_contents' of https://github.com/luisdelarosa/CocoaPods:
  Addressed comments from @irrationalfab: - simplified collection of unique prefix_header_contents - reduced sub specs in spec from 4 to 2 Removed inline documentation and added @notes and @todos. Added entry to Changelog.
  Fix issue #1449 by collecting the prefix_header_contents and uniq-ing them.
  Add integration test for issue #1449.
  Added two tests for issue #1449 - however both are passing at the unit level so I suspect that the issue will need to be tested at the integration test level.

Conflicts:
	CHANGELOG.md
[Integration] Update fixtures
[Bundle] Update
[Command::Spec] Encourage the adoption of gif screenshots

@orta & @neonichu would be proud!
Don't let the user run as root

Closes #1815