Replaced Travis CI with GitHub Actions

.github/workflows/pytest.yml

@@ -0,0 +1,96 @@
+# This workflow will install Python dependencies, run tests and lint with a variety of Python versions
+# For more information see: https://help.github.com/actions/language-and-framework-guides/using-python-with-github-actions
+
+name: PyTest Ludwig
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  pytest:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ ubuntu-latest ]
+        python-version: [ 3.6, 3.7, 3.8 ]
+        include:
+          - python-version: 3.6
+            tensorflow-version: 2.3.1
+          - python-version: 3.7
+            tensorflow-version: 2.4.0
+          - python-version: 3.8
+            tensorflow-version: nightly
+    env:
+      TENSORFLOW: ${{ matrix.tensorflow-version }}
+
+    timeout-minutes: 70
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python-version }}
+
+    - name: Setup Linux
+      if: runner.os == 'linux'
+      run: |
+        sudo apt-get install -y cmake libsndfile1
+
+    - name: Setup macOS
+      if: runner.os == 'macOS'
+      run: |
+        brew install libuv
+
+    - name: pip cache
+      uses: actions/cache@v2
+      with:
+        path: ~/.cache/pip
+        key: ${{ runner.os }}-pip-py${{ matrix.python-version }}-tf${{ matrix.tensorflow-version }}-${{ hashFiles('requirements*.txt') }}
+        restore-keys: |
+          ${{ runner.os }}-pip-py${{ matrix.python-version }}-tf${{ matrix.tensorflow-version }}-
+
+    - name: Install dependencies
+      env:
+        HOROVOD_WITH_TENSORFLOW: 1
+        HOROVOD_WITHOUT_MPI: 1
+        HOROVOD_WITHOUT_PYTORCH: 1
+        HOROVOD_WITHOUT_MXNET: 1
+      run: |
+        python --version
+        pip --version
+        python -m pip install -U pip
+        if [ $TENSORFLOW == "nightly" ]; then
+          cat requirements.txt | sed '/^tensorflow[>=<]/d' > requirements-temp && mv requirements-temp requirements.txt
+          cat requirements_horovod.txt | sed 's/\[tensorflow\]//g' > requirements-temp && mv requirements-temp requirements_horovod.txt
+          pip install tf-nightly
+          pip install --no-cache-dir git+https://github.com/horovod/horovod.git@master
+        else
+          pip install tensorflow==$TENSORFLOW
+        fi
+        pip install --no-build-isolation --no-use-pep517 ConfigSpace # temporary fix: https://github.com/automl/ConfigSpace/issues/173
+        pip install '.[test]'
+        pip list
+      shell: bash
+
+    - name: Reinstall Horovod if necessary
+      env:
+        HOROVOD_WITH_TENSORFLOW: 1
+        HOROVOD_WITHOUT_MPI: 1
+        HOROVOD_WITHOUT_PYTORCH: 1
+        HOROVOD_WITHOUT_MXNET: 1
+      run: |
+        HOROVOD_BUILT=$(python -c "import horovod.tensorflow; horovod.tensorflow.nccl_built(); print('SUCCESS')" || true)
+        if [[ $HOROVOD_BUILT != "SUCCESS" ]]; then
+          pip uninstall -y horovod
+          pip install --no-cache-dir git+https://github.com/horovod/horovod.git@master
+        fi
+        horovodrun --check-build
+      shell: bash
+
+    - name: Tests
+      run: |
+        pytest -v --timeout 300 --durations 10 tests

tests/integration_tests/test_postprocessing.py

@@ -17,11 +17,11 @@
 
 import os
 
-import mock
 import numpy as np
 import pandas as pd
 import pytest
 import tensorflow as tf
+from unittest import mock
 
 from ludwig.api import LudwigModel
 from ludwig.constants import NAME