Install necessary dependencies

flatpak/flatpak_build.sh

@@ -5,7 +5,10 @@ set -xe
 REPO=${REPO:-/repo}
 APPID=app.sublimemusic.SublimeMusic
 
+# TODO move these to the Docker container
 pip3 install requirements-parser
+flatpak install -y org.gnome.Platform//3.36
+flatpak install -y org.gnome.Sdk//3.36
 
 rm -rf flatpak-builder-tools
 git clone https://github.com/flatpak/flatpak-builder-tools.git