Fix tests

tests/fixture/failure/exercises/compFailure.rs

@@ -0,0 +1,3 @@
+fn main() {
+    let
+}

tests/fixture/failure/exercises/compNoExercise.rs

@@ -0,0 +1,2 @@
+fn main() {
+}

tests/fixture/failure/exercises/testFailure.rs

@@ -0,0 +1,4 @@
+#[test]
+fn passing() {
+    asset!(true);
+}

tests/fixture/failure/exercises/testNotPassed.rs

@@ -0,0 +1,4 @@
+#[test]
+fn not_passing() {
+    assert!(false);
+}