Returns the cache object, retrieving it from a local file if necessary
@return {Object}
function(readFromFile = false) {
      if (!readFromFile && this.__cache && typeof this.__cache == "object") {
        return this.__cache;
      }
      try {
        this.__cache = jsonlint.parse(fs.readFileSync(this.getCachePath(), "UTF-8"));
      } catch (e) {
        this.__cache = {
          repos : {
            list : [],
            data : {}
          },
          compat : {}
        };
      }
      return this.__cache;
    }