Update to latest credo. (#179)

Author: scouten

mix.lock

@@ -2,7 +2,7 @@
   "certifi": {:hex, :certifi, "1.0.0", "1c787a85b1855ba354f0b8920392c19aa1d06b0ee1362f9141279620a5be2039", [:rebar3], [], "hexpm"},
   "connection": {:hex, :connection, "1.0.4", "a1cae72211f0eef17705aaededacac3eb30e6625b04a6117c1b2db6ace7d5976", [:mix], [], "hexpm"},
   "coverex": {:hex, :coverex, "1.4.13", "d90833b82bdd6a1ec05a6d971283debc3dd9611957489010e4b1ab0071a9ee6c", [:mix], [{:hackney, "~> 1.5", [hex: :hackney, repo: "hexpm", optional: false]}, {:poison, "~> 1.5 or ~> 2.0 or ~> 3.0", [hex: :poison, repo: "hexpm", optional: false]}], "hexpm"},
-  "credo": {:hex, :credo, "0.7.3", "9827ab04002186af1aec014a811839a06f72aaae6cd5eed3919b248c8767dbf3", [:mix], [{:bunt, "~> 0.2.0", [hex: :bunt, repo: "hexpm", optional: false]}], "hexpm"},
+  "credo": {:hex, :credo, "0.8.1", "137efcc99b4bc507c958ba9b5dff70149e971250813cbe7d4537ec7e36997402", [:mix], [{:bunt, "~> 0.2.0", [hex: :bunt, repo: "hexpm", optional: false]}], "hexpm"},
   "db_connection": {:hex, :db_connection, "1.1.0", "b2b88db6d7d12f99997b584d09fad98e560b817a20dab6a526830e339f54cdb3", [:mix], [{:connection, "~> 1.0.2", [hex: :connection, repo: "hexpm", optional: false]}, {:poolboy, "~> 1.5", [hex: :poolboy, repo: "hexpm", optional: true]}, {:sbroker, "~> 1.0", [hex: :sbroker, repo: "hexpm", optional: true]}], "hexpm"},
   "decimal": {:hex, :decimal, "1.3.1", "157b3cedb2bfcb5359372a7766dd7a41091ad34578296e951f58a946fcab49c6", [:mix], [], "hexpm"},
   "dogma": {:hex, :dogma, "0.1.15", "5bceba9054b2b97a4adcb2ab4948ca9245e5258b883946e82d32f785340fd411", [:mix], [{:poison, ">= 2.0.0", [hex: :poison, repo: "hexpm", optional: false]}], "hexpm"},