Allow React v16 peer dependency (#203)

Author: lukeapage

package.json

@@ -38,8 +38,8 @@
     "timers": "fake"
   },
   "peerDependencies": {
-    "react": "^15.0.0",
-    "react-dom": "^15.0.0"
+    "react": "^15.0.0 || ^16.0.0",
+    "react-dom": "^15.0.0 || ^16.0.0"
   },
   "dependencies": {
     "chain-function": "^1.0.0",