Update devDep to rollup@1

Author: Andarist

package-lock.json

@@ -49,7 +49,7 @@
     "lint-staged": "^7.2.2",
     "mocha": "^5.2.0",
     "prettier": "^1.14.2",
-    "rollup": "^0.64.1",
+    "rollup": "^1.0.0",
     "rollup-plugin-buble": "^0.19.2",
     "rollup-plugin-json": "^3.0.0",
     "source-map": "^0.6.1",

package.json

@@ -49,7 +49,8 @@ describe('rollup-plugin-babel', function() {
 			)
 			.then(bundle => {
 				return bundle.generate(Object.assign({ format: 'cjs' }, generateOptions));
-			});
+			})
+			.then(({ output: [generated] }) => generated);
 	}
 
 	it('runs code through babel', () => {
@@ -120,7 +121,7 @@ describe('rollup-plugin-babel', function() {
 				plugins: [babelPlugin()],
 			})
 			.then(bundle => bundle.generate({ output: { format: 'esm' } }))
-			.then(({ code }) => {
+			.then(({ output: [{ code }] }) => {
 				assert.ok(/class Foo/.test(code));
 				assert.ok(/var Bar/.test(code));
 				assert.ok(!/class Bar/.test(code));