DATACMNS-362 - Resolved concurrency problem in Repositories.

We now create a copy of the keys before iterating over them in Repositories.getRepoInforFor(…) to make sure other threads can safely trigger lookupRepositoryFactoryInformationFor(…) which potentially alters the repositories instance variable. So far we haven't guarded against this scenario which caused a ConcurrentModificationException.
DATACMNS-358 - Test case for 1-index pages in PagedResourcesAssembler.

Added a test case to show that PagedResourcesAssembler correctly renders 1-indexed, empty pages after upgrading to Spring HATEOAS 0.8.0.BUILD-SNAPSHOT.