installCollectionData: Download and install collection data
In DramaAnalysis: Analysis of Dramatic Texts

Function to download collection data (grouped texts) from github. Overwrites (!) the current collections.

installCollectionData(
  dataDirectory = getOption("qd.datadir"),
  branchOrCommit = "master",
  repository = "metadata",
  baseUrl = "https://github.com/quadrama/"
)

`dataDirectory`	The data directory in which collection and data files are stored
`branchOrCommit`	The git branch, commit id, or tag that we want to download
`repository`	The repository
`baseUrl`	The github user (or group)