compile fix

ref: github.com/angular/angular-cli/issues/13550

Author: Vandivier

ui/angular.json

@@ -27,7 +27,7 @@
               "src/assets"
             ],
             "styles": [
-              "src/styles.sass"
+              "src/styles.scss"
             ],
             "scripts": [],
             "es5BrowserSupport": true
@@ -84,7 +84,7 @@
             "tsConfig": "src/tsconfig.spec.json",
             "karmaConfig": "src/karma.conf.js",
             "styles": [
-              "src/styles.sass"
+              "src/styles.scss"
             ],
             "scripts": [],
             "assets": [