use terser and clean-css directly

create a sourcemap as well by default

node_modules/estraverse/package.json

@@ -1,8 +1,8 @@
 {
   "_from": "estraverse@^4.2.0",
-  "_id": "estraverse@4.2.0",
+  "_id": "estraverse@4.3.0",
   "_inBundle": false,
-  "_integrity": "sha1-De4/7TH81GlhjOc0IJn8GvoL2xM=",
+  "_integrity": "sha512-39nnKffWz8xN1BU/2c79n9nB9HDzo0niYUqx6xyqUnyoAnQyyWpOTdZEeiCch8BBu515t4wp9ZmgVfVhn9EBpw==",
   "_location": "/estraverse",
   "_phantomChildren": {},
   "_requested": {
@@ -18,8 +18,8 @@
   "_requiredBy": [
     "/escodegen"
   ],
-  "_resolved": "https://registry.npmjs.org/estraverse/-/estraverse-4.2.0.tgz",
-  "_shasum": "0dee3fed31fcd469618ce7342099fc1afa0bdb13",
+  "_resolved": "https://registry.npmjs.org/estraverse/-/estraverse-4.3.0.tgz",
+  "_shasum": "398ad3f3c5a24948be7725e83d11a7de28cdbd1d",
   "_spec": "estraverse@^4.2.0",
   "_where": "F:\\projects\\p\\minifyfromhtml\\node_modules\\escodegen",
   "bugs": {
@@ -29,7 +29,7 @@
   "deprecated": false,
   "description": "ECMAScript JS AST traversal functions",
   "devDependencies": {
-    "babel-preset-es2015": "^6.3.13",
+    "babel-preset-env": "^1.6.1",
     "babel-register": "^6.3.13",
     "chai": "^2.1.1",
     "espree": "^1.11.0",
@@ -37,12 +37,12 @@
     "gulp-bump": "^0.2.2",
     "gulp-filter": "^2.0.0",
     "gulp-git": "^1.0.1",
-    "gulp-tag-version": "^1.2.1",
+    "gulp-tag-version": "^1.3.0",
     "jshint": "^2.5.6",
     "mocha": "^2.1.0"
   },
   "engines": {
-    "node": ">=0.10.0"
+    "node": ">=4.0"
   },
   "homepage": "https://github.com/estools/estraverse",
   "license": "BSD-2-Clause",
@@ -64,5 +64,5 @@
     "test": "npm run-script lint && npm run-script unit-test",
     "unit-test": "mocha --compilers js:babel-register"
   },
-  "version": "4.2.0"
+  "version": "4.3.0"
 }