Added a casadi function interface with tests (example to come) #1653

	#Checks if the code is formatted with black.

	name: is your code linted with black?
	on: [pull_request]
	jobs:
	build:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v1
	- name: Set up Python 3.10
	uses: actions/setup-python@v1
	with:
	python-version: '3.10'
	- name: Install Black
	run: pip install black
	- name: Run black --check .
	run: black . --exclude "external/*" --check -l120

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