Fix spelling errors in custom-set, word-count test names

exercises/custom-set/src/test/java/CustomSetTest.java

@@ -71,7 +71,7 @@ public class CustomSetTest {
 
     @Ignore("Remove to run test")
     @Test
-    public void emptySetIsASubsetOfNonEemptySet() {
+    public void emptySetIsASubsetOfNonEmptySet() {
         final boolean actual
                 = new CustomSet<>(Arrays.asList(1))
                         .isSubset(

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

@@ -47,7 +47,7 @@ public class WordCountTest {
 
     @Ignore("Remove to run test")
     @Test
-    public void countMultipleOccurences() {
+    public void countMultipleOccurrences() {
         expectedWordCount.put("one", 1);
         expectedWordCount.put("fish", 4);
         expectedWordCount.put("two", 1);