https://remix.ethereum.org/#gist=a9f7aa77650de07586e0e6241193a3ae&optimize=true&version=soljson-v0.6.6+commit.6c089d02.js&runs=200&evmVersion=null

issue.sol

/** This example code is designed to quickly deploy an example contract using Remix.
 *  If you have never used Remix, try our example walkthrough: https://docs.chain.link/docs/example-walkthrough
 *  You will need testnet ETH and LINK.
 *     - Kovan ETH faucet: https://faucet.kovan.network/
 *     - Kovan LINK faucet: https://kovan.chain.link/
 */
 
//  VRF Coordinator	0xdD3782915140c8f3b190B5D67eAc6dc5760C46E9
// Key Hash	0x6c3699283bda56ad74f6b855546325b68d482e983852a7a82979cc4807b641

pragma solidity 0.6.6;

import "https://raw.githubusercontent.com/smartcontractkit/chainlink/master/evm-contracts/src/v0.6/VRFConsumerBase.sol";
import "https://raw.githubusercontent.com/smartcontractkit/chainlink/develop/evm-contracts/src/v0.6/ChainlinkClient.sol";


contract RandomNumberConsumer is ChainlinkClient, VRFConsumerBase {
    
    bytes32 internal keyHash;
    uint256 internal fee;
    
    uint256 public randomResult;
    
    /**
     * Constructor inherits VRFConsumerBase
     * 
     * Network: Ropsten
     * Chainlink VRF Coordinator address: 0xdD3782915140c8f3b190B5D67eAc6dc5760C46E9
     * LINK token address:                0xa36085F69e2889c224210F603D836748e7dC0088
     * Key Hash: 0x6c3699283bda56ad74f6b855546325b68d482e983852a7a82979cc4807b641f4
     */
    constructor() 
        VRFConsumerBase(
            0xdD3782915140c8f3b190B5D67eAc6dc5760C46E9, // VRF Coordinator
            0xa36085F69e2889c224210F603D836748e7dC0088  // LINK Token
        ) public
    {
        keyHash = 0x6c3699283bda56ad74f6b855546325b68d482e983852a7a82979cc4807b641f4;
        fee = 0.1 * 10 ** 18; // 0.1 LINK
    }
    
    /** 
     * Requests randomness from a user-provided seed
     */
    function getRandomNumber(uint256 userProvidedSeed) public returns (bytes32 requestId) {
        require(LINK.balanceOf(address(this)) > fee, "Not enough LINK - fill contract with faucet");
        return requestRandomness(keyHash, fee, userProvidedSeed);
    }

    /**
     * Callback function used by VRF Coordinator
     */
    function fulfillRandomness(bytes32 requestId, uint256 randomness) internal override {
        randomResult = randomness;
    }
}