fixed creation of uglified/min js for core and docs

gulp-docs.js

@@ -55,9 +55,13 @@ export default function (gulp, options) {
         new Uglify(gulp, preset, prefix, {
           task: {name: 'vendor:uglify'},
           source: {options: {cwd: 'docs/assets/js/vendor'}},
-          options: {dest: 'docs-vendor.min.js'}
+          concat: {dest: 'docs-vendor.min.js'}
         })
-      )
+      ),
+      new Uglify(gulp, preset, prefix, {
+        task: {name: 'iife:uglify'},
+        source: { glob: '*.iife.js' }
+      })
     ),
     prefix)
 

gulpfile.babel.js

@@ -94,6 +94,11 @@ const js = new Aggregate(gulp, 'js',
         }
       })
     ),
+    new Uglify(gulp, preset, {
+      task: {name: 'iife:uglify'},
+      source: { glob: '*.iife.js' }
+    }),
+
     copyJsToDocs
   )
 )

package.json

@@ -43,7 +43,7 @@
     "babel-preset-es2015": "^6.6.0",
     "extend": "^3.0.0",
     "gulp": "github:gulpjs/gulp#4.0",
-    "gulp-pipeline": "^4.0",
+    "gulp-pipeline": ">=4.0.3",
     "moment": "^2.11.2"
   },
   "old-grunt-devDependencies": {