build: disallow namespace usage and bump stylelint (#9022)

package.json

@@ -118,7 +118,7 @@
     "scss-bundle": "^2.0.1-beta.7",
     "selenium-webdriver": "^3.6.0",
     "sorcery": "^0.10.0",
-    "stylelint": "^7.12.0",
+    "stylelint": "^8.4.0",
     "ts-node": "^3.0.4",
     "tsconfig-paths": "^2.3.0",
     "tslint": "^5.8.0",

tslint.json

@@ -82,6 +82,8 @@
     "import-blacklist": [true, "rxjs", "rxjs/operators"],
     // Avoids inconsistent linebreak styles in source files. Forces developers to use LF linebreaks.
     "linebreak-style": [true, "LF"],
+    // Namespaces are no allowed, because of Closure compiler.
+    "no-namespace": true,
 
     // Custom Rules
     "ts-loader": true,