add contributing guideline #876

	name: CI Tests

	on: [push, pull_request]

	jobs:
	GNU:
	runs-on: ${{ matrix.os }}
	strategy:
	fail-fast: false
	matrix:
	os: [ubuntu-22.04]
	compiler: [gfortran]

	env:
	FC: ${{ matrix.compiler }}

	name: ${{ matrix.os }} / ${{ matrix.compiler }}
	steps:
	- name: Checkout
	uses: actions/checkout@v2
	with:
	fetch-depth: 1

	- name: Checkout Submodules
	run: git submodule update --init --recursive

	- uses: actions/setup-python@v1
	with:
	python-version: '3.7'

	- name: Install Cmake
	run: pip3 install cmake

	- name: Install python dependencies
	run: pip3 install numpy pytest

	- name: Install blas, lapack and other dependencies
	run: sudo apt-get install libblas-dev liblapack-dev doxygen libgmp10 libgmpxx4ldbl libgmp-dev libopenblas-dev

	- name: Build
	run: \|
	mkdir -p build
	cd build
	cmake -DENABLE_GREENX_UNIT_TESTS=ON \
	-DGMPXX_INCLUDE_DIR=/usr/include/ \
	-DGMPXX_LIBRARY=/usr/lib/x86_64-linux-gnu/libgmpxx.so ../
	make -j$(nproc)

	- name: Run Tests
	run: \|
	cd python && pip install -e . && cd ../
	cd build
	ctest -j1 --output-on-failure
	# The build system exports GX_BUILD_DIR, but I do not know how to
	# propagate env vars between steps in Github Actions
	env:
	GX_BUILD_DIR: "/home/runner/work/greenX/greenX/build"

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