Apply suggestions from code review

Co-authored-by: Norman Rzepka <code@normanrz.com>

Author: konstibob

src/main/java/dev/zarr/zarrjava/store/S3Store.java

@@ -93,7 +93,7 @@ public ByteBuffer get(String[] keys, long start) {
         GetObjectRequest req = GetObjectRequest.builder()
                 .bucket(bucketName)
                 .key(resolveKeys(keys))
-                  .range(start < 0 //dependant on where we start either fetch last or first bytes
+                  .range(start < 0 // negative start implies indexing from the end, i.e. last bytes
                     ? String.format("bytes=%d", start)
                     : String.format("bytes=%d-", start))
                 .build();

src/test/java/dev/zarr/zarrjava/store/OnlineS3StoreTest.java

@@ -65,9 +65,7 @@ public void testReadSuffix() {
         StoreHandle storeHandle = storeHandleWithData();
         ByteBuffer fullBuffer = storeHandle.read();
         long size = fullBuffer.remaining();
-        if (size < 20) {
-            Assertions.fail("Store size is too small to test suffix read");
-        }
+        Assertions.assertsTrue(size >= 20, "Store size is too small to test suffix read");
 
         ByteBuffer suffixBuffer = storeHandle.read(-10);
         Assertions.assertEquals(10, suffixBuffer.remaining());