Use gulp-terser instead of gulp-uglify for ES2015

package.json

@@ -87,7 +87,6 @@
     "gulp-sourcemaps": "2.6.5",
     "gulp-stripbom": "1.0.5",
     "gulp-through": "0.4.0",
-    "gulp-uglify": "3.0.2",
     "gulp-util": "3.0.8",
     "gulp-zip": "5.0.1",
     "ifvisible.js": "1.0.6",
@@ -119,5 +118,8 @@
     "underscore": "1.9.2",
     "webpack": "4.41.5",
     "webpack-cli": "3.3.10"
+  },
+  "dependencies": {
+    "gulp-terser": "^1.2.0"
   }
 }

tasks/js.js

@@ -5,7 +5,7 @@ const concat = require('gulp-concat-util'),
 	header = require('gulp-header'),
 	rename = require('gulp-rename'),
 	replace = require('gulp-replace'),
-	uglify = require('gulp-uglify'),
+	terser = require('gulp-terser'),
 	plumber = require('gulp-plumber'),
 	gulpif = require('gulp-if'),
 	eol = require('gulp-eol'),
@@ -65,10 +65,8 @@ const jsMin = () =>
 		.pipe(replace(/"rainloop\/v\/([^/]+)\/static\/js\/"/g, '"rainloop/v/$1/static/js/min/"'))
 		.pipe(rename({ suffix: '.min' }))
 		.pipe(
-			uglify({
-				mangle: true,
-				compress: true,
-				ie8: false
+			terser({
+				output: {comments: false}
 			})
 		)
 		.pipe(eol('\n', true))