Added NewsDataBaseHelper. Changed news date from Date to String.
Implemented NewsListRetriever methods.
Changed date type from String back to Date in News and made necessary
changes to NewsListRetriver.
Modified newsDB.
Changed toggleBookmark input from species ID to scientific name and
commented out deleteBookmarks method.
Modified BookmarkManagerTest to fit the changes done to BookmarkManager.
Added NewsListRetrieverTest and modified a bit on BookmarkManagerTest.
update