function getConfigContent (configPath, baseDirectory) {
    if (!configPath) {
      return;
    }

    const resolvedPath = path.resolve(baseDirectory, configPath);
    const configBasename = path.basename(resolvedPath);

    if (!fs.existsSync(resolvedPath)) {
      return getNormalizedConfig(resolvedPath);
    }

    const content = readConfigContent(resolvedPath);
    return getNormalizedConfig(configBasename, content);
}
Get content of the configuration file
@param {String} configPath - partial path to configuration file
@param {String} directory - directory path which will be joined with config argument
@return {Object}