[#5] Remove testlib config file support

In order to make library as flexible as possible we will try to use
configuration methods similar to function `logging.dictConfig` from the
standard library. So, we won't support configuration file
`.neofs-testlib.yaml`, but will allow users to call `configure` method
that will load plugins and initialize library components.

Signed-off-by: Vladimir Domnich <v.domnich@yadro.com>

src/neofs_testlib/reporter/allure_handler.py

@@ -0,0 +1,34 @@
+import os
+from contextlib import AbstractContextManager
+from textwrap import shorten
+from typing import Any
+
+import allure
+from allure import attachment_type
+
+from neofs_testlib.reporter.interfaces import ReporterHandler
+
+
+class AllureHandler(ReporterHandler):
+    """Handler that stores test artifacts in Allure report."""
+
+    def step(self, name: str) -> AbstractContextManager:
+        name = shorten(name, width=70, placeholder="...")
+        return allure.step(name)
+
+    def attach(self, body: Any, file_name: str) -> None:
+        attachment_name, extension = os.path.splitext(file_name)
+        attachment_type = self._resolve_attachment_type(extension)
+
+        allure.attach(body, attachment_name, attachment_type)
+
+    def _resolve_attachment_type(self, extension: str) -> attachment_type:
+        """Try to find matching Allure attachment type by extension.
+
+        If no match was found, default to TXT format.
+        """
+        extension = extension.lower()
+        return next(
+            (allure_type for allure_type in attachment_type if allure_type.extension == extension),
+            attachment_type.TXT,
+        )