Issue #306: fix spelling mistakes in test names

exercises/nucleotide-count/src/test/java/NucleotideTest.java

     public ExpectedException thrown = ExpectedException.none();
     
     @Test
-    public void testEmptyDnaStringHasNoAdenosine() {
+    public void testEmptyDnaStringHasNoAdenine() {
         DNA dna = new DNA("");
         assertThat(dna.count('A'), is(0));
     }
 
     @Ignore
     @Test
-    public void testRepetitiveSequenceWithOnlyGuanosine() {
+    public void testRepetitiveSequenceWithOnlyGuanine() {
         DNA dna = new DNA("GGGGGGGG");
         Map<Character, Integer> counts = dna.nucleotideCounts();
         assertThat(counts.size(), is(4));
 
     @Ignore
     @Test
-    public void testCountsOnlyThymidine() {
+    public void testCountsOnlyThymine() {
         DNA dna = new DNA("GGGGGTAACCCGG");
         assertThat(dna.count('T'), is(1));
     }
 
     @Ignore
     @Test
-    public void testDnaCountsDoNotChangeAfterCountingAdenosine() {
+    public void testDnaCountsDoNotChangeAfterCountingAdenine() {
         DNA dna = new DNA("GATTACA");
         dna.count('A');
         Map<Character, Integer> counts = dna.nucleotideCounts();