build slightly more robust testing framework

.github/workflows/build.yaml

@@ -28,5 +28,5 @@ jobs:
         - name: Check formatting
           run: wake-format --dry-run --auto
 
-        - name: Run basic test
-          run: wake --in query -x 'single 5'
+        - name: Run tests
+          run: ./tests/test.sh

tests/query.wake

@@ -0,0 +1,10 @@
+package tests
+
+from wake import _
+from query import _
+
+export def runQueryTests _ =
+    require 4, Nil = single 4
+    else failWithError "Unexpected value for single"
+
+    Pass Unit

tests/test.sh

@@ -0,0 +1,5 @@
+#! /bin/bash
+
+set -e
+
+wake --in tests runQueryTests