Add base href to build script and test github actions

Author: jeanettephung

package.json

@@ -5,7 +5,7 @@
     "ng": "ng",
     "start": "ng serve",
     "build": "ng cache clean && ng build zingchart-angular-component",
-    "build:app": "ng cache clean && ng build",
+    "build:app": "ng cache clean && ng build --base-href=/zingchart-angular/",
     "watch": "ng build --watch --configuration development",
     "test": "ng test zingchart-angular-component",
     "publish": "cd dist/zingchart-angular && npm publish --access public",