Update Rollup to 0.20.1

package.json

@@ -31,6 +31,6 @@
     "ractive": "^0.7.3",
     "ractive-events-tap": "^0.2.0",
     "ractive-transitions-slide": "^0.2.1",
-    "rollup": "^0.19.1"
+    "rollup": "^0.20.1"
   }
 }

src/app/main.js

@@ -74,22 +74,26 @@ if ( supported ) {
 		/*global rollup */
 		rollup.rollup({
 			entry: 'main',
-			resolveId ( importee, importer ) {
-				if ( !importer ) return importee;
-				if ( importee[0] !== '.' ) return false;
-
-				return resolve( dirname( importer ), importee ).replace( /^\.\//, '' );
-			},
-			load: function ( id ) {
-				if ( id === 'main' ) return modules[0].code;
-				if ( extname( id ) === '' ) id += '.js';
-
-				const module = moduleById[ id ];
-
-				if ( !module ) throw new Error( `missing module ${id}` ); // TODO...
-
-				return module.code;
-			}
+			plugins: [
+				{
+					resolveId ( importee, importer ) {
+						if ( !importer ) return importee;
+						if ( importee[0] !== '.' ) return false;
+
+						return resolve( dirname( importer ), importee ).replace( /^\.\//, '' );
+					},
+					load: function ( id ) {
+						if ( id === 'main' ) return modules[0].code;
+						if ( extname( id ) === '' ) id += '.js';
+
+						const module = moduleById[ id ];
+
+						if ( !module ) throw new Error( `missing module ${id}` ); // TODO...
+
+						return module.code;
+					}
+				}
+			]
 		}).then( bundle => {
 			output.set({
 				imports: bundle.imports,