refactor: remove example and gulp, upgraded rollup build process, add prettier

Author: dgrubelic

.prettierrc.json

@@ -0,0 +1,9 @@
+{
+  "trailingComma": "es5",
+  "tabWidth": 2,
+  "semi": true,
+  "singleQuote": true,
+  "useTabs": false,
+  "printWidth": 80,
+  "arrowParens": "avoid"
+}

build/build.js

@@ -0,0 +1,121 @@
+var fs = require('fs');
+var rollup = require('rollup');
+var uglify = require('uglify-js');
+var buble = require('@rollup/plugin-buble');
+var uglify = require('rollup-plugin-uglify').uglify;
+var rollupBanner = require('rollup-plugin-banner').default;
+var package = require('../package.json');
+
+var banner =
+  'vue-authenticate v' +
+  package.version +
+  '\n' +
+  'https://github.com/dgrubelic/vue-authenticate\n' +
+  'Released under the MIT License.\n';
+
+function buildSource(inputOptions, outputOptions) {
+  rollup.rollup(inputOptions).then(function (bundle) {
+    return bundle.generate(outputOptions).then(function (output) {
+      bundle.write(outputOptions);
+    });
+  });
+}
+
+buildSource(
+  {
+    input: 'src/index.js',
+    plugins: [buble(), rollupBanner(banner)],
+  },
+  {
+    file: 'dist/vue-authenticate.js',
+    format: 'umd',
+    name: 'VueAuthenticate',
+  }
+);
+
+buildSource(
+  {
+    input: 'src/index.js',
+    plugins: [buble(), uglify(), rollupBanner(banner)],
+  },
+  {
+    file: 'dist/vue-authenticate.min.js',
+    format: 'umd',
+    name: 'VueAuthenticate',
+  }
+);
+
+buildSource(
+  {
+    input: 'src/index.js',
+    plugins: [rollupBanner(banner)],
+  },
+  {
+    file: 'dist/vue-authenticate.esm.js',
+    format: 'es',
+  }
+);
+
+buildSource(
+  {
+    input: 'src/index.js',
+    plugins: [rollupBanner(banner)],
+  },
+  {
+    file: 'dist/vue-authenticate.common.js',
+    format: 'cjs',
+  }
+);
+
+// rollup.rollup({
+//   input: 'src/index.js',
+//   plugins: [buble()]
+// })
+//   .then(function (bundle) {
+//     return bundle.write('dist/vue-authenticate.js', bundle.generate({
+//       format: 'umd',
+//       banner: banner,
+//       name: 'VueAuthenticate'
+//     }).code, bundle);
+//   })
+//   .then(function (bundle) {
+//     return bundle.write('dist/vue-authenticate.min.js',
+//       banner + '\n' + uglify.minify('dist/vue-authenticate.js').code,
+//       bundle);
+//   })
+//   .then(function (bundle) {
+//     return bundle.write('dist/vue-authenticate.es2015.js', bundle.generate({
+//       format: 'es',
+//       banner: banner,
+//       footer: 'export { VueAuthenticate };'
+//     }).code, bundle);
+//   })
+//   .then(function (bundle) {
+//     return bundle.write('dist/vue-authenticate.common.js', bundle.generate({
+//       format: 'cjs',
+//       banner: banner
+//     }).code, bundle);
+//   })
+//   .catch(logError);
+
+function write(dest, code, bundle) {
+  return new Promise(function (resolve, reject) {
+    fs.writeFile(dest, code, function (err) {
+      if (err) return reject(err);
+      console.log(blue(dest) + ' ' + getSize(code));
+      resolve(bundle);
+    });
+  });
+}
+
+function getSize(code) {
+  return (((code && code.length) || 0) / 1024).toFixed(2) + 'kb';
+}
+
+function logError(e) {
+  console.log(e);
+}
+
+function blue(str) {
+  return '\x1b[1m\x1b[34m' + str + '\x1b[39m\x1b[22m';
+}