save/load/removeを追加

source/src/main/java/one/nem/lacerta/source/file/FileManager.java

@@ -2,6 +2,7 @@ package one.nem.lacerta.source.file;
 
 import android.graphics.Bitmap;
 
+import java.io.File;
 import java.nio.file.Path;
 import java.util.List;
 
@@ -15,4 +16,8 @@ public interface FileManager {
     void createDir(String dirName);
     void removeDir(String dirName);
 
+    void saveBitmap(Path path, Bitmap bitmap);
+    Bitmap loadBitmap(Path path);
+    void removeBitmap(Path path);
+
 }