UX update for list of failed tests (#87)

The line "The following tests failed: " was appearing when there were
no test failures. This update simply updates it to only display when
there are failed tests.

Turkey/TestOutputFormat.cs

@@ -67,7 +67,7 @@ public async override Task PrintFailedTests()
                 Console.WriteLine("The following tests failed: ");
                 foreach(var test in failedTests)
                 {
-                   Console.WriteLine($"{string.Format("{0,-30}", test.Name)}({test.Duration})");
+                    Console.WriteLine($"{string.Format("{0,-30}", test.Name)}({test.Duration})");
                 }
             }
 

Turkey/TestRunner.cs

@@ -152,7 +152,10 @@ public async Task<TestResults> ScanAndRunAsync(List<TestOutput> outputs, string
                 await outputs.ForEachAsync(output => output.AfterRunningTestAsync(testName, testResult, testLog, testTimeWatch.Elapsed));
                 }
 
-            await outputs.ForEachAsync(outputs => outputs.PrintFailedTests());
+            if (results.Failed != 0 )
+            {
+                await outputs.ForEachAsync(outputs => outputs.PrintFailedTests());
+            }
 
             await outputs.ForEachAsync(output => output.AfterRunningAllTestsAsync(results));