Update to latest version of Experience builder (#11)

Developer edition v1.15

.github/workflows/build-app.yml

@@ -16,7 +16,7 @@ jobs:
         # IN OTHER WORDS, IT COULD BREAK AT ANY TIME.
         # THERE IS NO WARRANTY OR GUARANTEE THAT THIS COMMAND WILL WORK IN THE FUTURE.
         # ONLY USE THIS COMMAND IF YOU UNDERSTAND HOW IT IS BEING USED AND ARE COMFORTABLE FIXING IT IF IT BREAKS:
-        run: curl -o exb.zip "$(curl -s 'https://downloads.arcgis.com/dms/rest/download/secured/arcgis-experience-builder-1.13.zip?f=json&folder=software%2FExperienceBuilder%2F1.13' | python3 -c "import sys, json; print(json.load(sys.stdin)['url'])")"
+        run: curl -o exb.zip "$(curl -s 'https://downloads.arcgis.com/dms/rest/download/secured/arcgis-experience-builder-1.15.zip?f=json&folder=software%2FExperienceBuilder%2F1.15' | python3 -c "import sys, json; print(json.load(sys.stdin)['url'])")"
       - name: Unzip Experience Builder
         run: unzip -q exb.zip -d exb
       - name: Copy Custom Widgets
@@ -59,7 +59,7 @@ jobs:
           npm install --global serve
           echo "{\"trailingSlash\":true}" > serve.json
           serve . -p 5000 &
-          pageres http://localhost:5000/index.html 1024x768 --filename=screenshot --delay=10
+          pageres http://localhost:5000/index.html 1024x768 --filename=screenshot --delay=15
       - name: Deploy app zip to GH Pages
         uses: JamesIves/github-pages-deploy-action@v4
         with: