ci: travisci => github actions

.github/workflows/ci.yml

@@ -0,0 +1,39 @@
+name: CI
+on:
+  pull_request:
+  push:
+
+jobs:
+  main:
+    # Old ubuntu needed to support old elixir
+    runs-on: ubuntu-20.04
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - elixir_version: '1.16.2'
+            otp_version: '26.2.4'
+            lint: true
+          - elixir_version: '1.11.4'
+            otp_version: '22.3.4.27'
+    steps:
+      - uses: actions/checkout@v4
+      - uses: erlef/setup-beam@v1
+        with:
+          otp-version: ${{ matrix.otp_version }}
+          elixir-version: ${{ matrix.elixir_version }}
+      - run: mix deps.get --check-locked
+      - run: mix compile --warnings-as-errors
+        if: ${{ matrix.lint }}
+      - run: MIX_ENV=test mix compile --warnings-as-errors
+        if: ${{ matrix.lint }}
+      - run: MIX_ENV=prod mix compile --warnings-as-errors
+        if: ${{ matrix.lint }}
+      - run: mix format --check-formatted
+        if: ${{ matrix.lint }}
+      - run: mix deps.unlock --check-unused
+        if: ${{ matrix.lint }}
+      - run: mix deps.compile
+      - run: mix docs
+      - run: mix test
+      - run: mix dialyzer