Improve variable name to describe the bug in Codec 101.

Author: aherbert

src/test/java/org/apache/commons/codec/binary/Base64InputStreamTest.java

@@ -91,7 +91,7 @@ public void testCodec105() throws IOException {
      */
     @Test
     public void testCodec101() throws Exception {
-        final byte[] codec101 = StringUtils.getBytesUtf8(Base64TestData.CODEC_101_MULTIPLE_OF_3);
+        final byte[] codec101 = StringUtils.getBytesUtf8(Base64TestData.CODEC_101_INPUT_LENGTH_IS_MULTIPLE_OF_3);
         final ByteArrayInputStream bais = new ByteArrayInputStream(codec101);
         try (final Base64InputStream in = new Base64InputStream(bais)) {
             final byte[] result = new byte[8192];
@@ -120,7 +120,7 @@ public void testCodec101() throws Exception {
      */
     @Test
     public void testInputStreamReader() throws Exception {
-        final byte[] codec101 = StringUtils.getBytesUtf8(Base64TestData.CODEC_101_MULTIPLE_OF_3);
+        final byte[] codec101 = StringUtils.getBytesUtf8(Base64TestData.CODEC_101_INPUT_LENGTH_IS_MULTIPLE_OF_3);
         final ByteArrayInputStream bais = new ByteArrayInputStream(codec101);
         final Base64InputStream in = new Base64InputStream(bais);
         final InputStreamReader isr = new InputStreamReader(in);

src/test/java/org/apache/commons/codec/binary/Base64TestData.java

@@ -28,7 +28,11 @@
  */
 public class Base64TestData {
 
-    public static final String CODEC_101_MULTIPLE_OF_3 = "124";
+    /**
+     * A valid base 64 encoding that has a length that is a multiple of 3.
+     * @see <a href="https://issues.apache.org/jira/browse/CODEC-101">Codec 101</a>
+     */
+    public static final String CODEC_101_INPUT_LENGTH_IS_MULTIPLE_OF_3 = "124";
 
     public static final String CODEC_98_NPE
         = "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXpBQkNERUZHSElKS0xNTk9QUVJTVFVWV1hZWjAxMjM";