removal of unnecessary file, and composer update

vendor/twbs/bootstrap/js/tests/integration/rollup.bundle.js

@@ -0,0 +1,20 @@
+/* eslint-env node */
+
+const resolve = require('rollup-plugin-node-resolve')
+const commonjs = require('rollup-plugin-commonjs')
+const babel = require('rollup-plugin-babel')
+
+module.exports = {
+  input: 'js/tests/integration/bundle.js',
+  output: {
+    file: 'js/coverage/bundle.js',
+    format: 'iife'
+  },
+  plugins: [
+    resolve(),
+    commonjs(),
+    babel({
+      exclude: 'node_modules/**'
+    })
+  ]
+}