Remove the legacy multirepositories system

Signed-off-by: Aymeric Brisse <aymeric.brisse@perfect-memory.com>
Use YARD::Rake::YardocTask in Rakefile

Signed-off-by: Aymeric Brisse <aymeric.brisse@perfect-memory.com>
Update Spira.using_repository to ensure the repository restore

Signed-off-by: Aymeric Brisse <aymeric.brisse@perfect-memory.com>
Merge pull request #24 from PerfectMemory/feature-unique-repository

Feature unique repository