move driver and image metadata to libkpod

Signed-off-by: Ryan Cole <rcyoalne@gmail.com>

libkpod/driver/driver.go

@@ -0,0 +1,24 @@
+package driver
+
+import cstorage "github.com/containers/storage"
+
+type DriverData struct {
+	Name string
+	Data map[string]string
+}
+
+func GetDriverName(store cstorage.Store) (string, error) {
+	driver, err := store.GraphDriver()
+	if err != nil {
+		return "", err
+	}
+	return driver.String(), nil
+}
+
+func GetDriverMetadata(store cstorage.Store, layerID string) (map[string]string, error) {
+	driver, err := store.GraphDriver()
+	if err != nil {
+		return nil, err
+	}
+	return driver.Metadata(layerID)
+}