I'm using version 5.1.2 of `Comeonin` to hash passwords. The [documentation](https://github.com/riverrun/comeonin) says that either bcrypt\_elixir or argon2 are compatible hashing libraries. The problem I'm encountering happens with both.

If I try to use `Argon2.hash_pwd_salt` as recommended by the docs, I get the following error:

```
** (UndefinedFunctionError) function Comeonin.Argon2.hash_pwd_salt/1 is undefined or private. Did you mean one of:

  * hashpwsalt/1
  * hashpwsalt/2

```

BUT, if I follow the error and use `Argon2.hashpwsalt/1` I get:

```
** (ArgumentError) Comeonin.Argon2.hashpwsalt has been removed.
use Argon2.hash_pwd_salt instead.

```

This same set of errors occurs with bcrypt\_elixir. How do I use this library correctly?

For reference, this is my Mix file:

```
defp deps do
    [
      {:phoenix, "~> 1.4.7"},
      {:phoenix_pubsub, "~> 1.1"},
      {:phoenix_ecto, "~> 4.0"},
      {:ecto_sql, "~> 3.0"},
      {:postgrex, ">= 0.0.0"},
      {:phoenix_html, "~> 2.11"},
      {:phoenix_live_reload, "~> 1.2", only: :dev},
      {:gettext, "~> 0.11"},
      {:jason, "~> 1.0"},
      {:plug_cowboy, "~> 2.0"},
      {:guardian, "~> 1.2.1"},
      {:comeonin, "~> 5.1.2"},
      {:argon2_elixir, "~> 2.0"},
      {:ex_machina, "~> 2.3", only: :test},
      {:faker, "~> 0.12", only: :test}
    ]
  end

```