code: function parseFile (filePath, fileContent) {
    let config = null
    const extension = path.extname(filePath)
  
    if (extension === '.yml' || extension === '.yaml') {
      config = yaml.safeLoad(replaceEnvironmentVariables(fileContent))
    } else if (extension === '.js') {
      config = require(path.resolve(filePath)) // eslint-disable-line
    } else if (extension === '.json') {
      config = JSON.parse(replaceEnvironmentVariables(fileContent))
    } else {
      throw new Error(`${extension} is not supported as configuration file`)
    }
  
    return config
  }
docs: Parse a general configuration file
  These file extension ans formats are allowed:
  .yml, .js, .json
  
  If no fileContent is passed the file is read synchronously
  
  @param {String} filePath
  @param {String} fileContent
  
  @private
  @returns {Object} config