feat(rollup): add bundle size

rollup.config.js

@@ -3,12 +3,18 @@ import commonjs from 'rollup-plugin-commonjs';
 import babel from 'rollup-plugin-babel';
 import postcss from 'rollup-plugin-postcss';
 import autoprefixer from 'autoprefixer';
+import bundleSize from 'rollup-plugin-bundle-size';
 
 import pkg from './package.json';
 
 export default [{
 		input: 'src/index.js',
 		external: ['react', 'prop-types'],
+		onwarn(warning, rollupWarn) {
+			if (warning.code !== 'CIRCULAR_DEPENDENCY') {
+				rollupWarn(warning);
+			}
+		},
 		output: {
 			name: 'ReactGraph',
 			file: pkg.browser,
@@ -20,6 +26,7 @@ export default [{
 			}
 		},
 		plugins: [
+			bundleSize(),
 			postcss({
 				plugins: [autoprefixer()]
 			}),