The `UpdateCheckData` moved on the remote URL
The `UpdateCheckData` moved on the remote URL

Also installs `buildozer` under Python3 via `pip3` as some of the build
steps now requires Python3.
Note that python2.7 is still a required dependency from buildozer, refs:
https://github.com/kivy/buildozer/blob/586152c/buildozer/__init__.py#L582

f-droid/fdroiddata,f-droid/fdroiddata