added node-sass as dev dependency, needed after I removed grunt-sass

package.json

@@ -17,6 +17,7 @@
     "@babel/preset-react": "^7.0.0",
     "@babel/preset-typescript": "^7.1.0",
     "@rtsao/plugin-proposal-class-properties": "^7.0.1-patch.1",
+    "@types/classnames": "^2.2.6",
     "@types/d3": "^4.10.1",
     "@types/enzyme": "^3.1.13",
     "@types/jest": "^23.3.2",
@@ -26,7 +27,6 @@
     "@types/react-custom-scrollbars": "^4.0.5",
     "@types/react-dom": "^16.0.9",
     "@types/react-select": "^2.0.4",
-    "@types/classnames": "^2.2.6",
     "angular-mocks": "1.6.6",
     "autoprefixer": "^6.4.0",
     "axios": "^0.17.1",
@@ -52,9 +52,7 @@
     "grunt-cli": "~1.2.0",
     "grunt-contrib-clean": "~1.0.0",
     "grunt-contrib-compress": "^1.3.0",
-    "grunt-contrib-concat": "^1.0.1",
     "grunt-contrib-copy": "~1.0.0",
-    "grunt-contrib-cssmin": "~1.0.2",
     "grunt-exec": "^1.0.1",
     "grunt-newer": "^1.3.0",
     "grunt-notify": "^0.4.5",
@@ -75,6 +73,7 @@
     "ng-annotate-webpack-plugin": "^0.3.0",
     "ngtemplate-loader": "^2.0.1",
     "npm": "^5.4.2",
+    "node-sass": "^4.11.0",
     "optimize-css-assets-webpack-plugin": "^4.0.2",
     "phantomjs-prebuilt": "^2.1.15",
     "postcss-browser-reporter": "^0.5.0",