poker: straight to 5 in ascending order in example (#197)

* Straight to 5 was not in descending order

While working on this exercise in Delphi it seemed to me that straight to 5 was not correct.  However my tests were passing.  I discovered that this for instance was not being tested.

* Added testcase to test straight to 5

I believe this new test will fail if example is left with straight to 5 in ascending order.

* poker: corrects typos in Straight_to_5_against_a_pair_of_jacks

Author: rpottsoh

exercises/poker/Example.cs

@@ -52,7 +52,7 @@ private static int ScoreHand(Card[] cards)
 
         if (ranks.SequenceEqual(new[] { 14, 5, 4, 3, 2 }))
         {
-            ranks = new[] { 1, 2, 3, 4, 5 };
+            ranks = new[] { 5, 4, 3, 2, 1 };
         }
 
         var flush = suits.Distinct().Count() == 1;

exercises/poker/PokerTest.cs

@@ -168,4 +168,14 @@ public void Three_hand_with_tie()
         Assert.That(Poker.BestHands(new[] { spadeStraightTo9, diamondStraightTo9, threeOf4 }),
             Is.EqualTo(new[] { spadeStraightTo9, diamondStraightTo9 }));
     }
+
+    [Ignore("Remove to run test")]
+    [Test]
+    public void Straight_to_5_against_a_pair_of_jacks()
+    {
+        const string straightTo5 = "2S 4D 5C 3S AS";
+        const string twoJacks = "JD 8D 7D JC 5D";
+        Assert.That(Poker.BestHands(new[] { straightTo5, twoJacks }),
+            Is.EqualTo(new[] { straightTo5 }));
+    }
 }