word-count: add hint to @Ignore annotations

exercises/word-count/src/test/java/WordCountTest.java

         );
     }
 
-    @Ignore
+    @Ignore("Remove to run test")
     @Test
     public void countOneOfEach() {
         expectedWordCount.put("one", 1);
         );
     }
 
-    @Ignore
+    @Ignore("Remove to run test")
     @Test
     public void countMultipleOccurences() {
         expectedWordCount.put("one", 1);
         );
     }
 
-    @Ignore
+    @Ignore("Remove to run test")
     @Test
     public void ignorePunctuation() {
         expectedWordCount.put("car", 1);
 
     }
 
-    @Ignore
+    @Ignore("Remove to run test")
     @Test
     public void includeNumbers() {
         expectedWordCount.put("testing", 2);
         );
     }
 
-    @Ignore
+    @Ignore("Remove to run test")
     @Test
     public void normalizeCase() {
         expectedWordCount.put("go", 3);