Add boltdb implementation for packageset and db

pkg/package/database.go

@@ -18,12 +18,14 @@ package pkg
 // Database is a merely simple in-memory db.
 // FIXME: Use a proper structure or delegate to third-party
 type PackageDatabase interface {
+	PackageSet
+
 	Get(s string) (string, error)
 	Set(k, v string) error
 
 	Create([]byte) (string, error)
 	Retrieve(ID string) ([]byte, error)
 
-	GetPackage(ID string) (Package, error)
-	CreatePackage(p Package) (string, error)
+	FindPackage(name, version string) (Package, error)
+	UpdatePackage(p Package) error
 }