Added logo to README.md #609

	name: CI Tests

	on: [push, pull_request]

	jobs:
	GNU:
	runs-on: ${{ matrix.os }}
	strategy:
	fail-fast: false
	matrix:
	os: [ubuntu-20.04]
	compiler: [gfortran-9]

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

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

	- 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

	- name: Install Zofu Test Framework
	run: \|
	mkdir -p external && cd external
	git clone https://github.com/acroucher/zofu.git
	mkdir zofu/build && cd zofu/build
	cmake \
	-DCMAKE_BUILD_TYPE=release \
	-DCMAKE_INSTALL_PREFIX=/home/runner/work/greenX/greenX/external/zofu/install \
	-DZOFU_FORTRAN_MODULE_INSTALL_DIR:PATH=include \
	..
	make -j 4
	make install

	- name: Build
	run: \|
	mkdir -p build
	cd build
	cmake -DENABLE_UNITTESTS=ON -DZOFU_PATH=/home/runner/work/greenX/greenX/external/zofu/install ../
	make -j$(nproc) VERBOSE=1

	- 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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