Replace Travis with Github Actions

.github/workflows/2019.yml

@@ -0,0 +1,18 @@
+name: AOC 2019 test suite
+on:
+  push:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-python@v2
+        with:
+          python-version: 3.9
+      - name: Install dependencies
+        run: |
+          python -m pip install --upgrade pip
+          pip install -r 2019/requirements.txt
+      - name: Run Pytest
+        run: pytest 2019

.travis.yml

@@ -1,18 +0,0 @@
-dist: bionic
-language: python
-
-python:
-  - "3.9"
-
-# Custom directory, for the correct year
-before_install:
-  - cd 2019
-  - python -m pip install --upgrade pip
-
-script: pytest
-
-cache:
-  directories:
-    - $HOME/.cache/pip
-before_cache:
-  - rm -f $HOME/.cache/pip/log/debug.log