add github action for pytest and adjust coveragerc

Author: aleneum

.coveragerc

@@ -1,3 +1,4 @@
 [run]
 source = transitions
-include = */transitions/*
+include = */transitions/*
+relative_files = True

.github/workflows/pytest.yml

@@ -0,0 +1,47 @@
+# 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
+
+on:
+  push:
+    branches: [ master, dev-gha ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: [2.7, 3.7, 3.8, 3.9]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v2
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install dependencies
+      run: |
+        sudo apt-get install libgraphviz-dev graphviz
+        python -m pip install --upgrade pip
+        python -m pip install -r requirements.txt -r requirements_diagrams.txt 
+        python -m pip install -U -r requirements_test.txt
+    - name: Test with pytest
+      run: |
+        coverage run --source=transitions -m pytest --doctest-modules tests/
+    - name: Coveralls
+      uses: AndreMiras/coveralls-python-action@develop
+      with:
+        parallel: true
+        flag-name: Test with pytest
+      
+  coveralls_finish:
+    needs: test
+    runs-on: ubuntu-latest
+    steps:
+    - name: Coveralls Finished
+      uses: AndreMiras/coveralls-python-action@develop
+      with:
+        parallel-finished: true