Remove RecursiveIterator interface from hierarchical roles
Closes #4 because it no longer needs to implement RecursiveIterator
Add RecursiveRoleIterator
Pluggable traversal algorithm with strategy pattern
Add GeneratorStrategy
Require PHP 5.5.0 in GeneratorStrategyTest
Use ternary operator shortcut
Accept Traversable on RecursiveRoleIterator
It almost solves the Doctrine collections incompatibility
Move empty() check to the role itself
Rename traverseRoles -> getRolesIterator
Disallow duplicates
Set default strategy based on PHP Version
Merge pull request #5 from danizord/feature/traversal-strategies

Traversal strategies