v0.22.0

• feature: support flatten env source (#41)

  If you have the following environment variables:

  DATABASE=foo.example.com
  DATABASE_USER=john
  DATABASE_PASS=doe

  You can load them without any name conversion by using config.from.env(nested=false):

  object Root : ConfigSpec("") {
      val DATABASE by required<String>()
      val DATABASE_USER by required<String>()
      val DATABASE_PASS by required<String>()
  }
  
  Config {
      addSpec(Root)
  }.from.env(nested=false)

• fix: support numeric keys in source

  Now you can use numeric keys in source (use YAML as example):

  tree:
    1:
      myVal: true