Adds cross-version test framework #3

	name: Cross version tests

	on:
	push:
	branches: [master]
	pull_request:
	branches: [master]

	env:
	CC: gcc-10
	CXX: g++-10
	LD_LIBRARY_PATH: /usr/local/lib # this is where libhttpserver installs itself

	jobs:
	build:
	runs-on: ubuntu-latest

	strategy:
	matrix:
	client_version: ["v0.15", "v0.16", "master"]
	server_version: ["v0.15", "v0.16", "master"]

	steps:

	- name: Check out libhttpserver dependency
	uses: actions/checkout@v4
	with:
	repository: etr/libhttpserver
	ref: 0.19.0
	path: libhttpserver

	- name: Install Python dependencies
	uses: py-actions/py-dependency-install@v4

	- name: Install C++ dependencies
	run: \|
	sudo apt-get update
	sudo apt-get install -y libmicrohttpd-dev pybind11-dev

	- name: Build and install libhttpserver
	run: \|
	cd libhttpserver
	./bootstrap
	mkdir build
	cd build
	../configure
	make
	sudo make install

	- name: Client checkout
	uses: actions/checkout@v4
	with:
	path: client
	ref: ${{ matrix.client_version != 'current'
	&& matrix.client_version
	\|\| github.ref_name }}

	- name: Server checkout
	uses: actions/checkout@v4
	with:
	path: client
	ref: ${{ matrix.server_version != 'current'
	&& matrix.server_version
	\|\| github.ref_name }}

	- name: Build client
	working-directory: client
	run: \|
	cmake -B build -DCMAKE_MODULE_PATH=/usr/local/share/cmake/Modules
	cmake --build build

	- name: Build server
	working-directory: server
	run: \|
	cmake -B build -DCMAKE_MODULE_PATH=/usr/local/share/cmake/Modules
	cmake --build build

	- name: Test
	working-directory: client/build
	run: ctest --verbose

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