add basic functionality and corresponding tests

tests/test_configs.py

@@ -0,0 +1,36 @@
+from pathlib import Path
+
+import pytest
+
+from dopt_basics import configs
+
+
+@pytest.fixture(scope="module")
+def config_file(root_data_folder) -> Path:
+    pth = root_data_folder / "config.toml"
+    assert pth.exists()
+    assert pth.is_file()
+
+    return pth
+
+
+def test_load_toml_SuccessPath(config_file):
+    cfg = configs.load_toml(config_file)
+    assert isinstance(cfg, dict)
+    assert "test" in cfg
+    assert cfg["test"]["entry"] == "test123"
+
+
+def test_load_toml_SuccessStringPath(config_file):
+    str_pth = str(config_file)
+    cfg = configs.load_toml(str_pth)
+    assert isinstance(cfg, dict)
+    assert "test" in cfg
+    assert cfg["test"]["entry"] == "test123"
+
+
+def test_load_toml_FailWrongPath(tmp_path):
+    wrong_pth = tmp_path / "config.toml"
+
+    with pytest.raises(FileNotFoundError):
+        _ = configs.load_toml(wrong_pth)