fix references for diffcyt paper (now Weber2019a in .bib file) and HDCytoData package (now Weber2019b); these were previously both Weber2019, which meant that HDCytoData package wasn't showing in the references list
also minor fix to reference for clustering comparison paper Weber2016 (volume number)
Weber2019ain.bibfile) and HDCytoData package (nowWeber2019b); these were previously bothWeber2019, which meant that HDCytoData package wasn't showing in the references listWeber2016(volume number)