All examples now have at least the required `+catalogBreadcrumbs` and `+catalogIsPrimaryDemo`. All examples in the same breadcrumbs path have only one primary demo. There should be only one `-catalogDescription` attached to the primary demo.
Closes#1897
* Integrate SwiftLint in the Catalog.
* Update the disabled SwiftLint rules.
* Reference a local swiftlint.yml symlink.
This prevents us from getting warnings about code style violations from the other demos.
* Fix SwiftLint violations in the Catalog and Components.
* Ignore the `third_party` directory when running the linter.
We should not have to deal with warnings in code we may not be able to fix easily.
* Integrate SwiftLint into Shrine.
Additionally, fix a number of warnings introduced.
* Run SwiftLint on Travis.
* Enable many of the previously disabled rules and correct them.
* Fix control statement violations from SwiftLint.
