update credo

Author: mitchellhenke

mix.lock

@@ -3,7 +3,7 @@
   "certifi": {:hex, :certifi, "1.1.0", "c9b71a547016c2528a590ccfc28de786c7edb74aafa17446b84f54e04efc00ee", [:rebar3], []},
   "cowboy": {:hex, :cowboy, "1.1.2", "61ac29ea970389a88eca5a65601460162d370a70018afe6f949a29dca91f3bb0", [:rebar3], [{:cowlib, "~> 1.0.2", [hex: :cowlib, optional: false]}, {:ranch, "~> 1.3.2", [hex: :ranch, optional: false]}]},
   "cowlib": {:hex, :cowlib, "1.0.2", "9d769a1d062c9c3ac753096f868ca121e2730b9a377de23dec0f7e08b1df84ee", [:make], []},
-  "credo": {:hex, :credo, "0.8.1", "137efcc99b4bc507c958ba9b5dff70149e971250813cbe7d4537ec7e36997402", [:mix], [{:bunt, "~> 0.2.0", [hex: :bunt, optional: false]}]},
+  "credo": {:hex, :credo, "0.8.4", "4e50acac058cf6292d6066e5b0d03da5e1483702e1ccde39abba385c9f03ead4", [:mix], [{:bunt, "~> 0.2.0", [hex: :bunt, optional: false]}]},
   "dialyxir": {:hex, :dialyxir, "0.5.0", "5bc543f9c28ecd51b99cc1a685a3c2a1a93216990347f259406a910cf048d1d7", [:mix], []},
   "earmark": {:hex, :earmark, "1.2.2", "f718159d6b65068e8daeef709ccddae5f7fdc770707d82e7d126f584cd925b74", [:mix], []},
   "ex_doc": {:hex, :ex_doc, "0.16.2", "3b3e210ebcd85a7c76b4e73f85c5640c011d2a0b2f06dcdf5acdb2ae904e5084", [:mix], [{:earmark, "~> 1.1", [hex: :earmark, optional: false]}]},