Merge pull request #700 from cantaloupe-project/bugfix/s3-content-type

Include S3 object content type in attributes

src/main/java/edu/illinois/library/cantaloupe/source/S3Source.java

@@ -326,6 +326,7 @@ private S3ObjectAttributes getObjectAttributes() throws IOException {
                         .build());
                 objectAttributes              = new S3ObjectAttributes();
                 objectAttributes.length       = response.contentLength();
+                objectAttributes.contentType  = response.contentType();
                 objectAttributes.lastModified = response.lastModified();
             } catch (NoSuchBucketException | NoSuchKeyException e) {
                 throw new NoSuchFileException(info.toString());