double builder should build from string

src/test/java/redis/clients/jedis/tests/BuilderFactoryTest.java

@@ -0,0 +1,14 @@
+package redis.clients.jedis.tests;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import redis.clients.jedis.BuilderFactory;
+
+public class BuilderFactoryTest extends Assert {
+    @Test
+    public void buildDouble() {
+        Double build = BuilderFactory.DOUBLE.build("1.0".getBytes());
+        assertEquals(new Double(1.0), build);
+    }
+}