fix bug

src/components/DataCard.js

 import React from 'react';
-import { Card, Col, Row, Button, Tooltip } from 'react-bootstrap';
+import { Card, Col, Row, Button } from 'react-bootstrap';
 import { FaMoneyBillAlt, FaArrowUp, FaArrowDown, FaUserFriends, FaFileCsv } from 'react-icons/fa';
 import { AreaChart, Area, XAxis, YAxis, ResponsiveContainer, Tooltip } from 'recharts';
 import withWindowDimensions from '../utils/withWindowDimensions';