add testcase for issue #2130

src/test/java/com/alibaba/json/bvt/issue_2100/Issue2130.java

+package com.alibaba.json.bvt.issue_2100;
+
+import com.alibaba.fastjson.JSON;
+import com.alibaba.fastjson.JSONObject;
+import junit.framework.TestCase;
+
+public class Issue2130 extends TestCase {
+    public void test_for_issue() throws Exception {
+        String str = "{\"score\":0.000099369485}";
+        JSONObject object = JSON.parseObject(str);
+        assertEquals("{\"score\":0.000099369485}", object.toJSONString());
+    }
+}