Update rna-transcription to 1.3.0 and add empty sequence test (exercism#1516) (exercism#1574)

* Update rna-transcription to 1.3.0 and add empty sequence test (exercism#1516)

* remove version comment in tests

Author: alis0nc

exercises/rna-transcription/.meta/version

@@ -1 +1 @@
-1.2.0
+1.3.0

exercises/rna-transcription/src/test/java/RnaTranscriptionTest.java

@@ -13,6 +13,12 @@ public void setUp() {
         rnaTranscription = new RnaTranscription();
     }
 
+    @Test
+    public void testEmptyRnaSequence() {
+        assertEquals("", rnaTranscription.transcribe(""));
+    }
+
+    @Ignore("Remove to run test")
     @Test
     public void testRnaTranscriptionOfCytosineIsGuanine() {
         assertEquals("G", rnaTranscription.transcribe("C"));