bump 1.9.1 (#27)

Author: dylanjha

README.md

@@ -21,7 +21,7 @@ Add `mux` to your list of dependencies in `mix.exs`:
 ```elixir
 def deps do
  [
- {:mux, "~> 1.9.0"}
+ {:mux, "~> 1.9.1"}
  ]
 end
 ```

mix.exs

@@ -3,7 +3,7 @@ defmodule Mux.MixProject do
 
  @github_url "https://github.com/muxinc/mux-elixir"
 
- @version "1.9.0"
+ @version "1.9.1"
 
  def project do
  [