added cpy-cli dependency and updated build script

Following advice from galaxy maintainer :

- Switch to cpy-cli to use instead of cp (should prevent the differences in cp behaviour)

config/plugins/visualizations/fits_image_viewer/package.json

@@ -8,9 +8,10 @@
     "license": "AFL-3.0",
     "dependencies": {
         "aladin-lite-galaxy": "^1.0.0",
-        "parcel-bundler": "^1.4.1"
+        "parcel-bundler": "^1.4.1",
+        "cpy-cli": "^5.0.0"
     },
     "scripts": {
-        "build": "mkdir -p static/dist; cp -r node_modules/aladin-lite-galaxy static/dist/. && parcel build src/script.js -d static"
+        "build": "cpy --flat node_modules/aladin-lite-galaxy static/dist/aladin-lite-galaxy && parcel build src/script.js -d static"
     }
 }