Basic refactoring of migration tests.
Return correct id for migration.
Correctly pass timestamp around during initialization process.
Fixed test for identity comparision.
Added correct Migration#to_s implementation.
Fixed sorting tests by converting to timestamp before. All migration tests running again!
Removed migration set tests.
Removed algorithm and context test. Algorithm is tested in algorithm up and context does not exist anymore.
Removed test_migration_5_algorithm because it depends on old follows/graph idea.
Renamed test migration loader.
Renamed folder of test migrations from test_migrations to migrations.
Removed second example model. We should use only one example model, to avoid clutter.
Merge branch 'migration_refactoring' into develop

Conflicts:
	test/test_migration_loader.rb