reduce memory usage

Reduce memory usage by storing the filename as string instead of
individual tags.

pdb-utils/src/test/java/org/lucares/utils/MiniMapTest.java

@@ -1,24 +0,0 @@
-package org.lucares.utils;
-
-import org.testng.Assert;
-import org.testng.annotations.Test;
-
-@Test
-public class MiniMapTest {
-	public void testInsertGet()
-	{
-		final MiniMap<String, String> map = new MiniMap<>();
-
-		String key1 = "key1";
-		String key2 = "key2";
-		String value1 = "value1";
-		String value2 = "value1";
-		
-		
-		map.put(key1, value1);
-		map.put(key2, value2);
-		
-		Assert.assertEquals(map.get(key1), value1);
-		Assert.assertEquals(map.get(key2), value2);
-	}
-}