Unchecked dependency

gistfile1.txt

Unchecked dependencies for environment dev:
* postgrex (Hex package)
  the dependency postgrex defined

  > In mix.exs:
    {:postgrex, ">= 0.0.0", [hex: :postgrex]}

  does not match the requirement specified

  > In deps/ecto/mix.exs:
    {:postgrex, "~> 0.8.3", [optional: true, hex: :postgrex]}

  Ensure they match or specify one of the above in your Test.Mixfile deps and set `override: true`
** (Mix) Can't continue due to errors on dependencies