Update elixir.yml

Author: princemaple

.github/workflows/elixir.yml

@@ -2,23 +2,42 @@ name: Elixir CI
 
 on:
   push:
-    branches: [ master ]
+    branches: [main]
   pull_request:
-    branches: [ master ]
+    branches: [main]
 
 jobs:
   build:
-
     runs-on: ubuntu-latest
-
+    strategy:
+      matrix:
+        elixir: ['1.12', '1.11', '1.10', '1.9']
+        otp: ['24.0', '23.2', '22.3']
+        exclude:
+          - elixir: '1.9'
+            otp: '24.0'
+          - elixir: '1.10'
+            otp: '24.0'
     steps:
-    - uses: actions/checkout@v2
-    - name: Setup elixir
-      uses: erlef/setup-elixir@v1
-      with:
-        elixir-version: "1.11"
-        otp-version: "23"
-    - name: Install Dependencies
-      run: mix deps.get
-    - name: Run Tests
-      run: mix test
+      - uses: actions/checkout@v2
+
+      - name: Setup BEAM
+        uses: erlef/setup-beam@v1
+        with:
+          elixir-version: ${{ matrix.elixir }}
+          otp-version: ${{ matrix.otp }}
+
+      - name: Restore dependencies cache
+        uses: actions/cache@v2
+        with:
+          path: |
+            deps
+            _build
+          key: ${{ runner.os }}-mix-${{ hashFiles('**/mix.lock') }}
+          restore-keys: ${{ runner.os }}-mix-
+
+      - name: Install Dependencies
+        run: mix deps.get
+
+      - name: Run Tests
+        run: mix test