Add tool Base Converter.

app/src/test/java/com/fatapp/oxygentoolbox/MethodTest.java

@@ -0,0 +1,14 @@
+package com.fatapp.oxygentoolbox;
+
+import static org.junit.Assert.assertEquals;
+
+import com.fatapp.oxygentoolbox.util.HexConversionUtils;
+
+import org.junit.Test;
+
+public class MethodTest {
+    @Test
+    public void decimalToBaseTest() {
+        assertEquals(HexConversionUtils.decimalToBase("2.2", 2), "10.00110011001100110011001100110011001100110011001100");
+    }
+}

app/src/test/java/com/fatapp/oxygentoolbox/TempTest.java

@@ -1,14 +1,21 @@
 package com.fatapp.oxygentoolbox;
 
+import static org.junit.Assert.assertEquals;
+
 import org.junit.Test;
 
 import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
 import java.nio.charset.StandardCharsets;
 
-public class Tester {
+public class TempTest {
     @Test
     public void urlEncodeTest() throws UnsupportedEncodingException {
         System.out.println(URLEncoder.encode(" ", StandardCharsets.UTF_8.toString()));
     }
+
+    @Test
+    public void hexTest() {
+        assertEquals(Integer.parseInt("a", 36), 10);
+    }
 }