Upgrade Credo to 1.0

[fahchen]

When I run codeclimate with the credo, get the error:

** (UndefinedFunctionError) function Credo.Check.Readability.AliasOrder.base_priority/0 is undefined (module Credo.Check.Readability.AliasOrder is not available)
    Credo.Check.Readability.AliasOrder.base_priority()
    lib/credo/check/runner.ex:96: anonymous fn/2 in Credo.Check.Runner.exclude_low_priority_checks/2
    (elixir) lib/enum.ex:2985: Enum.reject_list/2
    (elixir) lib/enum.ex:2988: Enum.reject_list/2
    lib/credo/check/runner.ex:92: Credo.Check.Runner.exclude_low_priority_checks/2
    lib/credo/check/runner.ex:48: Credo.Check.Runner.prepare_config/1
    (codeclimate_credo) lib/command.ex:15: Codeclimate.Command.run/1
    (elixir) lib/kernel/cli.ex:105: anonymous fn/3 in Kernel.CLI.exec_fun/2