replaced AvanzuAdminTheme with AdminLTE bundle #201 (#202)

composer.json

@@ -5,12 +5,12 @@
     "description": "Kimai Time-Tracking 2",
     "require": {
         "php": "^7.1.3",
+        "ext-intl": "*",
         "ext-pdo": "*",
         "ext-pdo_sqlite": "*",
-        "ext-intl": "*",
-        "avanzu/admin-theme-bundle": "dev-kevinpapst",
         "beberlei/DoctrineExtensions": "^1.0",
         "erusev/parsedown": "^1.6",
+        "kevinpapst/adminlte-bundle": "^0.3.0",
         "ocramius/proxy-manager": "2.1.1",
         "sensio/framework-extra-bundle": "^5.1",
         "symfony/asset": "^4.0",