Changed peerDependency of react to not warn when using v16 (rjsf-team#729)

Author: dxlbnl

package.json

@@ -37,7 +37,7 @@
  "node": ">=6"
  },
  "peerDependencies": {
- "react": "^15.0.0"
+ "react": ">=15"
  },
  "dependencies": {
  "ajv": "^5.2.3",