Add Uniswap V3 Fixture (#95)

* add basic Uniswap V3 fixture

* add createPool to fixture

* add quoter

* add getTokenOrder helper

* add addLiquidityWide helper function

* add external contracts

* sort imports

* fix imports

* improve comments

* use exact values in tests

* split uniswap contracts into v2/v3 folders

* review changes

* add weth and wbtc price in initialize function

Author: ncitron

contracts/protocol/integration/oracles/UniswapPairPriceAdapter.sol

@@ -26,7 +26,7 @@ import { AddressArrayUtils } from "../../../lib/AddressArrayUtils.sol";
 import { IController } from "../../../interfaces/IController.sol";
 import { IPriceOracle } from "../../../interfaces/IPriceOracle.sol";
 import { IUniswapV2Pair } from "../../../interfaces/external/IUniswapV2Pair.sol";
-import { UniswapV2Library } from "../../../../external/contracts/uniswap/lib/UniswapV2Library.sol";
+import { UniswapV2Library } from "../../../../external/contracts/uniswap/v2/lib/UniswapV2Library.sol";
 import { PreciseUnitMath } from "../../../lib/PreciseUnitMath.sol";
 import { ResourceIdentifier } from "../../lib/ResourceIdentifier.sol";