Bump poison from 3.1.0 to 5.0.0

Bumps [poison](https://github.com/devinus/poison) from 3.1.0 to 5.0.0.
- [Release notes](https://github.com/devinus/poison/releases)
- [Commits](devinus/poison@3.1.0...5.0.0)

---
updated-dependencies:
- dependency-name: poison
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

mix.exs

@@ -31,7 +31,7 @@ defmodule Devdocs.Mixfile do
   defp deps do
     [
       {:ex_link_header, "~> 0.0.5"},
-      {:poison, "~> 3.1"},
+      {:poison, "~> 5.0"},
       {:httpoison, "~> 1.8.0"},
       {:joken, "~> 2.3"},
       {:jose, "~> 1.8"},

mix.lock

@@ -19,7 +19,7 @@
   "mimerl": {:hex, :mimerl, "1.2.0", "67e2d3f571088d5cfd3e550c383094b47159f3eee8ffa08e64106cdf5e981be3", [:rebar3], [], "hexpm", "f278585650aa581986264638ebf698f8bb19df297f66ad91b18910dfc6e19323"},
   "nimble_parsec": {:hex, :nimble_parsec, "1.2.2", "b99ca56bbce410e9d5ee4f9155a212e942e224e259c7ebbf8f2c86ac21d4fa3c", [:mix], [], "hexpm", "98d51bd64d5f6a2a9c6bb7586ee8129e27dfaab1140b5a4753f24dac0ba27d2f"},
   "parse_trans": {:hex, :parse_trans, "3.3.1", "16328ab840cc09919bd10dab29e431da3af9e9e7e7e6f0089dd5a2d2820011d8", [:rebar3], [], "hexpm", "07cd9577885f56362d414e8c4c4e6bdf10d43a8767abb92d24cbe8b24c54888b"},
-  "poison": {:hex, :poison, "3.1.0", "d9eb636610e096f86f25d9a46f35a9facac35609a7591b3be3326e99a0484665", [:mix], [], "hexpm", "fec8660eb7733ee4117b85f55799fd3833eb769a6df71ccf8903e8dc5447cfce"},
+  "poison": {:hex, :poison, "5.0.0", "d2b54589ab4157bbb82ec2050757779bfed724463a544b6e20d79855a9e43b24", [:mix], [{:decimal, "~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "11dc6117c501b80c62a7594f941d043982a1bd05a1184280c0d9166eb4d8d3fc"},
   "ssl_verify_fun": {:hex, :ssl_verify_fun, "1.1.6", "cf344f5692c82d2cd7554f5ec8fd961548d4fd09e7d22f5b62482e5aeaebd4b0", [:make, :mix, :rebar3], [], "hexpm", "bdb0d2471f453c88ff3908e7686f86f9be327d065cc1ec16fa4540197ea04680"},
   "unicode_util_compat": {:hex, :unicode_util_compat, "0.7.0", "bc84380c9ab48177092f43ac89e4dfa2c6d62b40b8bd132b1059ecc7232f9a78", [:rebar3], [], "hexpm", "25eee6d67df61960cf6a794239566599b09e17e668d3700247bc498638152521"},
 }