Package installation after v1.0.0

[heuristicus]

The PR at #114 separates wrapper code from, as mentioned in #113. The wrapper code is now included in a python-only submodule (https://github.com/bdaiinstitute/spot_wrapper) which must be manually built. To use version 1.0.0 of this repository, you will need to run

cd spot_ros
git submodule init
git submodule update
pip3 install -e spot_wrapper

Once you have installed the wrapper with the -e flag, any changes in the wrapper will be available immediately. You can pull changes to the wrapper and it should function without having to reinstall it.

The usage of everything else in the package should be as it was before - we've simply moved the wrapper. Please open an issue if you find anything that isn't working.