DEV: upgrades babel to 6.26.3 (#7651)

This is the last version of the 6.x babel branch.

To achieve this I used https://github.com/babel/babel-standalone witht he following patch:

diff --git a/gulpfile.js b/gulpfile.js
index 2121b5f..c40bfa3 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -74,24 +74,23 @@ const minifyAndRename = lazypipe()
   .pipe(uglify)
   .pipe(rename, { extname: '.min.js' });

-gulp.task('default', ['build']);
-gulp.task('build', ['build-babel', 'build-babili']);
-
-gulp.task('build-babel', cb => {
-  pump([
-    gulp.src('src/index.js'),
-    webpackBuild('babel.js', 'Babel', require('./package.json').version),
-    gulp.dest('.'),
-    minifyAndRename(),
-    gulp.dest('.'),
-  ], cb);
-});
-gulp.task('build-babili', cb => {
-  pump([
-    gulp.src('src/babili.js'),
-    webpackBuild('babili.js', 'Babili', require('./packages/babili-standalone/package.json').version),
-    gulp.dest('packages/babili-standalone/'),
-    minifyAndRename(),
-    gulp.dest('packages/babili-standalone/'),
-  ], cb);
-});
+  gulp.task('build-babel', gulp.series(cb => {
+    pump([
+      gulp.src('src/index.js'),
+      webpackBuild('babel.js', 'Babel', require('./package.json').version),
+      gulp.dest('.'),
+      minifyAndRename(),
+      gulp.dest('.'),
+    ], cb);
+  }));
+  gulp.task('build-babili', gulp.series(cb => {
+    pump([
+      gulp.src('src/babili.js'),
+      webpackBuild('babili.js', 'Babili', require('./packages/babili-standalone/package.json').version),
+      gulp.dest('packages/babili-standalone/'),
+      minifyAndRename(),
+      gulp.dest('packages/babili-standalone/'),
+    ], cb);
+  }));
+gulp.task('build', gulp.series('build-babel', 'build-babili'));
+gulp.task('default', gulp.series('build'));
diff --git a/package.json b/package.json
index f2414d2..854cfad 100644
--- a/package.json
+++ b/package.json
@@ -17,7 +17,7 @@
     "url": "git+https://github.com/Daniel15/babel-standalone.git"
   },
   "devDependencies": {
-    "babel-core": "6.26.0",
+    "babel-core": "6.26.3",
     "babel-helper-builder-react-jsx": "6.23.0",
     "babel-loader": "6.4.1",
     "babel-plugin-check-es2015-constants": "6.22.0",
@@ -123,7 +123,7 @@
     "babel-preset-stage-1": "6.24.1",
     "babel-preset-stage-2": "6.24.1",
     "babel-preset-stage-3": "6.24.1",
-    "gulp": "^3.9.1",
+    "gulp": "^4",
     "gulp-rename": "^1.2.2",
     "gulp-uglify": "^2.0.1",
     "jest": "^18.1.0",

and then ran:
yarn
yarn run build

This commit is contained in: