Release v2.1.0.

package.json

 {
   "name": "@uniswap/sdk",
   "license": "MIT",
-  "version": "2.0.6",
+  "version": "2.1.0",
   "description": "🛠 An SDK for building applications on top of Uniswap.",
   "main": "dist/index.js",
   "typings": "dist/index.d.ts",