Updated the RequestText" contains a full stop" to "ends with the correct end-token".

TestCentre/PropertyTests.fs

@@ -103,11 +103,12 @@
             Check.Quick results
 
         [<Property>]
-        let ``RequestText returns a string which contains a full stop`` () =
+        let ``RequestText returns a string which ends with the correct end-token`` () =
             let test () =
                 Pancake.RequestTextAsync (ValidGibberishLevelInput()) (ValidSentencesInput())
                 |> Async.RunSynchronously
-            let results = Assert.Contains(".", test())
+                |> EndsAsIntended
+            let results = Assert.True(test())
             Check.Quick results
 
         [<Property>]