Make test cases that use assertJump fail if they dont fail

test/BasicToken.js

@@ -25,8 +25,9 @@ contract('BasicToken', function(accounts) {
     try {
       let transfer = await token.transfer(accounts[1], 101);
     } catch(error) {
-      assertJump(error);
+      return assertJump(error);
     }
+    assert.fail('should have thrown before');
   });
 
 });