Add CI logic for testing the latest dependencies

This way we can catch breaking upstream changes early and adapt the code sooner rather than later.

It works by checking if the CI variable TEST_LATEST is set to "true" all dependencies is bumped to the latest version, before tests are run. The plan is to test the latest dependencies on a schedule.

Fix #67 (closed)

ci/bump_dependencies_to_latest.py

+#!/usr/bin/env python3
+import subprocess
+
+import tomli
+
+with open("pyproject.toml", "rb") as f:
+    pyproject = tomli.load(f)
+poetry = pyproject.get("tool").get("poetry")
+
+deps = poetry.get("dependencies").keys()
+deps = list(filter(("python").__ne__, deps))
+deps = list(map(lambda d: f"{d}@latest", deps))
+dev_deps = poetry.get("dev-dependencies").keys()
+dev_deps = list(map(lambda d: f"{d}@latest", dev_deps))
+
+subprocess.run(["poetry", "add"] + deps, check=True)
+subprocess.run(["poetry", "add", "-D"] + dev_deps, check=True)