feature: Fixes linux CI & adds 5.7

Author: NeedleInAJayStack

.github/workflows/test.yml

@@ -33,18 +33,35 @@ jobs:
         run: swift build
       - name: Run tests
         run: swift test
-  linux-build:
-    name: Build and test ${{ matrix.swift }}  on ${{ matrix.os }}
+        
+  # ubuntu-latest is ubuntu-22.04 currently. Swift versions older than 5.7 don't have builds for 22.04. https://www.swift.org/download/ 
+  ubuntu-old:
+    name: Build ${{ matrix.swift }} on ${{ matrix.os }}
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-latest]
+        os: [ubuntu-20.04] 
         swift: ["5.4", "5.5", "5.6"]
     steps:
-      - uses: swift-actions/setup-swift@v1
-        with:
-          swift-version: ${{ matrix.swift }}
-      - uses: actions/checkout@v2
-      - name: Test
-        run: swift test
+    - uses: swift-actions/setup-swift@v1
+      with:
+        swift-version: ${{ matrix.swift }}
+    - uses: actions/checkout@v3
+    - name: Test
+      run: swift test
+
+  ubuntu-latest:
+    name: Build ${{ matrix.swift }} on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest] 
+        swift: ["5.7"]
+    steps:
+    - uses: swift-actions/setup-swift@v1
+      with:
+        swift-version: ${{ matrix.swift }}
+    - uses: actions/checkout@v3
+    - name: Test
+      run: swift test