Add babel task and move to src directory

tasks/gulp-babelify.js

@@ -0,0 +1,16 @@
+import gulp from 'gulp';
+import babel from 'gulp-babel';
+
+const ES2015_SOURCE = 'common/script/src/**/*.js';
+const ES2015_DIST = 'common/dist/scripts/';
+
+gulp.task('babel:common', () => {
+  return gulp.src(ES2015_SOURCE)
+    .pipe(babel())
+    .pipe(gulp.dest(ES2015_DIST));
+});
+
+gulp.task('babel:common:watch', () => {
+  gulp.watch([ES2015_SOURCE], ['babel:common']);
+});
+