diff --git a/.github/workflows/python-package.yml b/.github/workflows/python-package.yml
index a4e456ad2a36708a04722acb51f8441880e9d443..71463e777c56f3e1e24207a3c2d57bd249820617 100644
--- a/.github/workflows/python-package.yml
+++ b/.github/workflows/python-package.yml
@@ -2,7 +2,7 @@ name: Python package
 
 on:
   pull_request:
-    branches: [ master, develop ]
+    branches: [ main, develop ]
 
 jobs:
   build:
@@ -20,6 +20,7 @@ jobs:
           python-version: ${{ matrix.python-version }}
       - name: Install dependencies
         run: |
+          ls -la
           python -m pip install --upgrade pip
           pip install tox
           pip install --upgrade -r requirements.txt
diff --git a/README.md b/README.md
deleted file mode 100644
index 4be6789d0478434e15827aa7310a70ce57f6daca..0000000000000000000000000000000000000000
--- a/README.md
+++ /dev/null
@@ -1 +0,0 @@
-# asr-benchmarks
\ No newline at end of file
diff --git a/sziszapangma/core/wer/wer_embedding_calculator.py b/sziszapangma/core/wer/wer_embedding_calculator.py
index 30dc82a07e036c5e7c9b27bfea2295aba867d3e8..5f371b7f519dc6f17b618c0a19e252cefd900089 100644
--- a/sziszapangma/core/wer/wer_embedding_calculator.py
+++ b/sziszapangma/core/wer/wer_embedding_calculator.py
@@ -19,7 +19,10 @@ class WerEmbeddingCalculator(WerCalculator):
         self._distance_calculator = CosineDistanceCalculator(
             embedding_transformer)
 
-    def _calculate_distance_for_word_step(self, step_words: StepWords) -> float:
+    def _calculate_distance_for_word_step(
+        self,
+        step_words: StepWords
+    ) -> float:
         return self._distance_calculator.calculate_distance_for_words(
             step_words.reference_word,
             step_words.hypothesis_word
diff --git a/sziszapangma/integration/__pycache__/metrics_calculator.cpython-38.pyc b/sziszapangma/integration/__pycache__/metrics_calculator.cpython-38.pyc
deleted file mode 100644
index 64abcc4563ec492321106b4c30b36abb903f4342..0000000000000000000000000000000000000000
Binary files a/sziszapangma/integration/__pycache__/metrics_calculator.cpython-38.pyc and /dev/null differ
diff --git a/sziszapangma/integration/metrics_calculator.py b/sziszapangma/integration/metrics_calculator.py
deleted file mode 100644
index 0d145c0386dfa66712f76128bef604991883ba30..0000000000000000000000000000000000000000
--- a/sziszapangma/integration/metrics_calculator.py
+++ /dev/null
@@ -1,34 +0,0 @@
-"""Main calculator of metrics."""
-from typing import List, Dict
-
-
-class MetricsCalculator:
-    """Main calculator of metrics."""
-
-    _calculate_classic_wer: bool
-
-    def __init__(self, calculate_classic_wer):
-        self._calculate_classic_wer = calculate_classic_wer
-
-    @staticmethod
-    def _run_wer_calculations(
-        gold_transcript: List[Dict[str, any]],
-        asr_result: List[str]
-    ) -> float:
-        return simple_calculate_wer(
-            reference=[it[_WORD] for it in gold_transcript],
-            hypothesis=[it for it in asr_result],
-        )
-
-    def calculate_metrics(
-        self,
-        gold_transcript: List[Dict[str, any]],
-        asr_result: List[str]
-    ) -> Dict[str, any]:
-        """Calculate all metrics for data sample."""
-        metrics = dict()
-        if self._calculate_classic_wer:
-            metrics[_CLASSIC_WER] = MetricsCalculator._run_wer_calculations(
-                gold_transcript, asr_result)
-        # TODO: put additional metrics here
-        return metrics
diff --git a/sziszapangma/integration/path_filter.py b/sziszapangma/integration/path_filter.py
index aa9db3a8bd1ca104e043a9a2915a25ee483d8c91..1ac6eb41e04b1fddd8930ea00c5db93321e32dc4 100644
--- a/sziszapangma/integration/path_filter.py
+++ b/sziszapangma/integration/path_filter.py
@@ -38,9 +38,11 @@ class ExtensionPathFilter(PathFilter):
         """
         Implementation of searching files with extension.
         """
+        path_generator = Path(self._root_directory).glob(
+            f'**/*.{self._extension}')
         all_files = [
             str(it)
-            for it in Path(self._root_directory).glob(f'**/*.{self._extension}')
+            for it in path_generator
         ]
         return all_files \
             if self._files_limit is None \
diff --git a/sziszapangma/integration/repository/mongo_experiment_repository.py b/sziszapangma/integration/repository/mongo_experiment_repository.py
index 73f3f6f05fcd32b607f70ccabf04b875ffb1a4ad..19c11aa4d7215642840e8b3ca85b15b08f4fb167 100644
--- a/sziszapangma/integration/repository/mongo_experiment_repository.py
+++ b/sziszapangma/integration/repository/mongo_experiment_repository.py
@@ -1,4 +1,4 @@
-from typing import Optional, List, Set
+from typing import Optional, Set
 
 from pymongo import MongoClient
 from pymongo.database import Database
diff --git a/sziszapangma/integration/task/gold_transcript_task.py b/sziszapangma/integration/task/gold_transcript_task.py
index 291eb80e1eac3077ce438380b05ffac0520665bd..0b407b4767d05c703a05475a58a113efbd247005 100644
--- a/sziszapangma/integration/task/gold_transcript_task.py
+++ b/sziszapangma/integration/task/gold_transcript_task.py
@@ -1,6 +1,5 @@
 from sziszapangma.integration.gold_transcript_processor import \
     GoldTranscriptProcessor
-from sziszapangma.integration.record_path_provider import RecordPathProvider
 from sziszapangma.integration.repository.experiment_repository \
     import ExperimentRepository
 from sziszapangma.integration.task.processing_task import ProcessingTask
diff --git a/tests/test_classic_wer.py b/tests/test_classic_wer.py
index 90a29bc60254ef54c6ca335629772ca4e6862d72..cdead597bc6e4e2a20db4f2089fbdc90985a8f31 100644
--- a/tests/test_classic_wer.py
+++ b/tests/test_classic_wer.py
@@ -32,9 +32,9 @@ def test_classic_calculate_wer_steps():
         StepWords('recognize', 'nice'),
         StepWords('speech', 'beach')]
     step_types = [
-        StepType.CORRECT, StepType.DELETION, StepType.CORRECT, StepType.CORRECT,
-        StepType.INSERTION, StepType.INSERTION, StepType.SUBSTITUTION,
-        StepType.SUBSTITUTION]
+        StepType.CORRECT, StepType.DELETION, StepType.CORRECT,
+        StepType.CORRECT, StepType.INSERTION, StepType.INSERTION,
+        StepType.SUBSTITUTION, StepType.SUBSTITUTION]
 
     assert len(wer_result[1]) == 8
     assert [it.step_type for it in wer_result[1]] == step_types
diff --git a/tox.ini b/tox.ini
index c5655d8732339d25937df8285fa3c7fb046f6df6..4dc38fb541aa720338639b776759f9d0205a9e7e 100644
--- a/tox.ini
+++ b/tox.ini
@@ -1,10 +1,6 @@
 [tox]
-envlist = py38, py39, flake8
-
-;[travis]
-;python =
-;    3.9: py39
-;    3.8: py38
+envlist = flake8
+skipsdist = True
 
 [testenv:flake8]
 basepython = python
@@ -20,6 +16,8 @@ deps =
 ; requirements.txt with the pinned versions and uncomment the following line:
 ;     -r{toxinidir}/requirements.txt
 commands =
+    ls -la
     pip install -U pip
-    pytest --basetemp={envtmpdir}
+    pytest
+;    pytest --basetemp={envtmpdir}