github actions tests: initial (#4469)

* github actions tests: initial

* build: tests: add codecov action

.github/workflows/tests.yaml

@@ -0,0 +1,42 @@
+name: Tests build
+
+on: [push, pull_request]
+
+env:
+  DVC_TEST: "true"
+  HOMEBREW_NO_AUTO_UPDATE: 1
+  SHELL: /bin/bash
+
+jobs:
+  tests:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-18.04, windows-2019, macos-10.15]
+        pyv: [3.6, 3.7, 3.8]
+        exclude:
+          - os: windows-2019
+            pyv: 3.8
+    steps:
+    - uses: actions/[email protected]
+    - name: Set up Python
+      uses: actions/[email protected]
+      with:
+        python-version: ${{ matrix.pyv }}
+    - name: install
+      run: |
+        pip install ".[all,tests]"
+    - name: setup git
+      run: |
+        git config --global user.email "[email protected]"
+        git config --global user.name "DVC Tester"
+    - name: run tests
+      run: python -m tests -n=2 --cov-report=xml
+    - name: upload coverage report
+      if: github.event.name == 'push'
+      uses: codecov/[email protected]
+      with:
+        file: ./coverage.xml
+        fail_ci_if_error: true
+
+