Add GitHub Actions checks, remove TravisCI

Author: goodmami

.github/workflows/checks.yml

@@ -0,0 +1,40 @@
+name: tests
+
+on:
+  push:
+    branches: [ develop ]
+  pull_request:
+    branches: [ develop ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: [3.6, 3.7, 3.8, 3.9]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v1
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install .[tests]
+    - name: Lint with flake8
+      run: |
+        # stop the build if there are Python syntax errors or undefined names
+        flake8 delphin --count --select=E9,F63,F7,F82 --show-source --statistics
+        # exit-zero treats all errors as warnings. PEP-8 says 99 chars is a good width
+        flake8 delphin --count --exit-zero --extend-ignore E221 --max-line-length=99 --statistics
+        # E221 = whitespace before operator
+        # disabled for now: --max-complexity=10
+    - name: Test with pytest
+      run: |
+        pytest .
+    - name: Type-check with mypy
+      run: |
+        mypy delphin --namespace-packages --explicit-package-bases --ignore-missing-imports

.travis.yml

@@ -2,7 +2,7 @@
 
 [![PyPI Version](https://img.shields.io/pypi/v/pydelphin.svg)](https://pypi.org/project/PyDelphin/)
 ![Python Support](https://img.shields.io/pypi/pyversions/pydelphin.svg)
-[![Build Status](https://travis-ci.org/delph-in/pydelphin.svg)](https://travis-ci.org/delph-in/pydelphin)
+[![Test Status](https://github.com/delph-in/pydelphin/workflows/tests/badge.svg)](https://github.com/delph-in/pydelphin/actions?query=workflow%3A%22tests%22)
 [![Documentation Status](https://readthedocs.org/projects/pydelphin/badge/?version=latest)](https://pydelphin.readthedocs.io/en/latest/?badge=latest)
 
 [DELPH-IN](http://delph-in.net) is an international consortium of