Bump kaba-scss + fix return type

Author: Jannik Zschiesche

package.json

@@ -19,7 +19,7 @@
         "test": "npm run-script build && ava"
     },
     "optionalDependencies": {
-        "kaba-scss": "^3.1.0",
+        "kaba-scss": "^3.3.2",
         "webpack-bundle-analyzer": "^3.6.0"
     },
     "dependencies": {
@@ -50,7 +50,7 @@
     "devDependencies": {
         "@types/terser-webpack-plugin": "^2.2.0",
         "ava": "^2.4.0",
-        "kaba-scss": "^3.1.0",
+        "kaba-scss": "^3.3.2",
         "webpack-bundle-analyzer": "^3.6.0"
     },
     "engines": {

src/runner/SassRunner.ts

@@ -24,7 +24,7 @@ export class SassRunner
      *
      * @return {Promise<boolean>} whether the build was successful and error-free
      */
-    public async run () : Promise<boolean|null>
+    public async run () : Promise<boolean|void>
     {
         const entries = Object.keys(this.buildConfig.entries);