mved stack into linear category

linear/stack_test.go

@@ -0,0 +1,17 @@
+package stack
+
+import (
+	"testing"
+)
+
+func TestPush(t *testing.T) {
+	s := Stack[int]{}
+	s.Push(1)
+	s.Push(2)
+	s.Push(3)
+
+	if len(s.Container) != 3 {
+		t.Errorf("expected 2 items, got %d", len(s.Container))
+	}
+
+}