v1.6.0

This release brings a new endpoint that make sure that you can't shoot yourself in the foot by calling registerLoader multiple times and a few tests improvements.

Total issues resolved: 7

• 145: Memory leak in AnnotationRegistry::registerLoader() when called multiple times thanks to @TriAnMan
• 146: Import error on @experimental Annotation thanks to @aturki
• 147: Ignoring @experimental annotation used by Symfony 3.3 CacheAdapter thanks to @aturki
• 151: Remove duplicate code in DCOM58Test thanks to @tuanphpvn
• 161: Prevent loading class_exists multiple times thanks to @jrjohnson
• 162: Add registerUniqueLoader to AnnotationRegistry thanks to @jrjohnson
• 163: Use assertDirectoryExists and assertDirectoryNotExists thanks to @carusogabriel

Thanks to everyone involved in this release.