Rewrite tests

tests/unit/test_parser.py

@@ -1,4 +1,10 @@
 from ergogen_footprint_converter.parser import Parser
+import pytest
+from pathlib import Path
 
+def test_parser_filenotexists():
+    with pytest.raises(Exception, match=r".*Given path is not a file.*"):
+        Parser(Path("nop"))
+    
 def test_parser():
     None