ci: use github actions for simply CI

.github/workflows/ci.yml

@@ -0,0 +1,28 @@
+name: ci
+
+on:
+  push:
+  schedule:
+  - cron: '0 4 * * *'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v1
+    - name: Set up Python 3.8
+      uses: actions/setup-python@v1
+      with:
+        python-version: 3.8
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install pipenv
+        pipenv install --dev --deploy
+    - name: Formatting
+      run: |
+        # check that the source files are formatted correctly
+        pipenv run yapf -q *.py
+    - name: Linting
+      run: |
+        pipenv run pylint *.py

README.md

@@ -1,5 +1,7 @@
 # kube-stale-resources
 
+![Build Status](https://github.com/cmur2/kube-stale-resources/workflows/ci/badge.svg)
+
 This is a utility to detect stale resources in [Kubernetes](https://kubernetes.io/) clusters between resources from YAML manifests supplied via local file or stdin (target state) and a Kubernetes cluster (live state).
 All resources that exist in the live state but not in the target state are considered *stale* as they deviate from the intended state of the Kubernetes cluster (closed world assumption). It is intended as a complement to [kubectl diff](https://kubernetes.io/blog/2019/01/14/apiserver-dry-run-and-kubectl-diff/).