Structural changes

src/pyrmv/errors/unknown_error.py

@@ -0,0 +1,15 @@
+class UnknownError(Exception):
+    """Exception raised but error is not known.
+
+    ### Attributes:
+        * errorCode: Client error code from HAFAS ReST Request Errors.
+        * errorText: Description of an error occurred.
+    """
+
+    def __init__(self, errorCode: str, errorText: str):
+        self.errorCode = errorCode
+        self.errorText = errorText
+        super().__init__(self.errorText)
+
+    def __str__(self):
+        return f'{self.errorCode} -> {self.errorText}'