sbt-btbt-workshop-017.scala

override def projectSettings = Seq(
  // Required settings that must be defined by the project utilizing the plugin
  tweeterConsumerKey := {
    tweeterConsumerKey.??(undefinedKeyError(tweeterConsumerKey.key)).value
  },
  tweeterConsumerSecret := {
    tweeterConsumerSecret.??(undefinedKeyError(tweeterConsumerSecret.key)).value
  },
  tweeterAccessToken := {
    tweeterAccessToken.??(undefinedKeyError(tweeterAccessToken.key)).value
  },
  tweeterAccessTokenSecret := {
    tweeterAccessTokenSecret.??(undefinedKeyError(tweeterAccessTokenSecret.key)).value
  },
  ...