use terser and clean-css directly

create a sourcemap as well by default

node_modules/escodegen/package.json

@@ -1,8 +1,8 @@
 {
   "_from": "escodegen@^1.11.0",
-  "_id": "escodegen@1.11.1",
+  "_id": "escodegen@1.14.1",
   "_inBundle": false,
-  "_integrity": "sha512-JwiqFD9KdGVVpeuRa68yU3zZnBEOcPs0nKW7wZzXky8Z7tffdYUHbe11bPCV5jYlK6DVdKLWLm0f5I/QlL0Kmw==",
+  "_integrity": "sha512-Bmt7NcRySdIfNPfU2ZoXDrrXsG9ZjvDxcAlMfDUgRBjLOWTuIACXPBFJH7Z+cLb40JeQco5toikyc9t9P8E9SQ==",
   "_location": "/escodegen",
   "_phantomChildren": {},
   "_requested": {
@@ -18,20 +18,20 @@
   "_requiredBy": [
     "/jsdom"
   ],
-  "_resolved": "https://registry.npmjs.org/escodegen/-/escodegen-1.11.1.tgz",
-  "_shasum": "c485ff8d6b4cdb89e27f4a856e91f118401ca510",
+  "_resolved": "https://registry.npmjs.org/escodegen/-/escodegen-1.14.1.tgz",
+  "_shasum": "ba01d0c8278b5e95a9a45350142026659027a457",
   "_spec": "escodegen@^1.11.0",
   "_where": "F:\\projects\\p\\minifyfromhtml\\node_modules\\jsdom",
   "bin": {
-    "esgenerate": "./bin/esgenerate.js",
-    "escodegen": "./bin/escodegen.js"
+    "esgenerate": "bin/esgenerate.js",
+    "escodegen": "bin/escodegen.js"
   },
   "bugs": {
     "url": "https://github.com/estools/escodegen/issues"
   },
   "bundleDependencies": false,
   "dependencies": {
-    "esprima": "^3.1.3",
+    "esprima": "^4.0.1",
     "estraverse": "^4.2.0",
     "esutils": "^2.0.2",
     "optionator": "^0.8.1",
@@ -40,7 +40,7 @@
   "deprecated": false,
   "description": "ECMAScript code generator",
   "devDependencies": {
-    "acorn": "^4.0.4",
+    "acorn": "^7.1.0",
     "bluebird": "^3.4.7",
     "bower-registry-client": "^1.0.0",
     "chai": "^3.5.0",
@@ -86,5 +86,5 @@
     "test": "gulp travis",
     "unit-test": "gulp test"
   },
-  "version": "1.11.1"
+  "version": "1.14.1"
 }