Bump credo from 1.1.4 to 1.1.5 (elixirs#296)

Bumps [credo](https://github.com/rrrene/credo) from 1.1.4 to 1.1.5.
- [Release notes](https://github.com/rrrene/credo/releases)
- [Changelog](https://github.com/rrrene/credo/blob/master/CHANGELOG.md)
- [Commits](rrrene/credo@v1.1.4...v1.1.5)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Author: dependabot-preview[bot]

mix.lock

@@ -1,6 +1,6 @@
 %{
   "bunt": {:hex, :bunt, "0.2.0", "951c6e801e8b1d2cbe58ebbd3e616a869061ddadcc4863d0a2182541acae9a38", [:mix], [], "hexpm"},
-  "credo": {:hex, :credo, "1.1.4", "c2f3b73c895d81d859cec7fcee7ffdb972c595fd8e85ab6f8c2adbf01cf7c29c", [:mix], [{:bunt, "~> 0.2.0", [hex: :bunt, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm"},
+  "credo": {:hex, :credo, "1.1.5", "caec7a3cadd2e58609d7ee25b3931b129e739e070539ad1a0cd7efeeb47014f4", [:mix], [{:bunt, "~> 0.2.0", [hex: :bunt, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm"},
   "dialyxir": {:hex, :dialyxir, "0.5.1", "b331b091720fd93e878137add264bac4f644e1ddae07a70bf7062c7862c4b952", [:mix], [], "hexpm"},
   "earmark": {:hex, :earmark, "1.4.1", "07bb382826ee8d08d575a1981f971ed41bd5d7e86b917fd012a93c51b5d28727", [:mix], [], "hexpm"},
   "ex_doc": {:hex, :ex_doc, "0.21.2", "caca5bc28ed7b3bdc0b662f8afe2bee1eedb5c3cf7b322feeeb7c6ebbde089d6", [:mix], [{:earmark, "~> 1.3.3 or ~> 1.4", [hex: :earmark, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}], "hexpm"},