Merge pull request #22 from PragTob/patch-1

There is no released 2.2 version

README.md

@@ -17,7 +17,7 @@ You can install `machinist` by adding it to your list of dependencies in `mix.e
 ```elixir
 def deps do
  [
- {:machinist, "~> 2.2.0"}
+ {:machinist, "~> 2.1"}
  ]
 end
 ```