helpers: Improve ACL asserts

Modify `_it.shouldBeAllowed` to include the actual status code
in the assertion error.

Modify `_it.shouldBeDenied` to assert the exact value of the status
code. Expect the status code configured via `app.get('aclErrorStatus')`,
add a parameter allowing callers to override this value.

Author: Miroslav Bajtoš

lib/helpers.js

@@ -211,18 +211,18 @@ _it.shouldBeAllowed = function() {
   it('should be allowed', function() {
     assert(this.req);
     assert(this.res);
-    //status 200 -> 399
-    var status = this.res.statusCode;
-    assert(status >= 200 && status <= 399);
+    // expect success - status 2xx or 3xx
+    expect(this.res.statusCode).to.be.within(100, 399);
   });
 }
 
 _it.shouldBeDenied = function() {
   it('should not be allowed', function() {
     assert(this.res);
-    //if in list
-    var status = this.res.statusCode;
-    assert([403,401].indexOf(status) > -1);
+    var expectedStatus = this.aclErrorStatus ||
+      this.app && this.app.get('aclErrorStatus') ||
+      401;
+    expect(this.res.statusCode).to.equal(expectedStatus);
   });
 }