update dialyxir config

Author: mitchellhenke

.gitignore

@@ -3,3 +3,5 @@
 erl_crash.dump
 *.ez
 /doc
+/priv/plts/*.plt
+/priv/plts/*.plt.hash

.travis.yml

@@ -35,3 +35,4 @@ cache:
   directories:
     - .mix
     - _build
+    - priv/plts

mix.exs

@@ -10,7 +10,11 @@ defmodule Sentry.Mixfile do
       package: package(),
       deps: deps(),
       elixirc_paths: elixirc_paths(Mix.env()),
-      dialyzer: [plt_add_deps: :transitive, plt_add_apps: [:mix]],
+      dialyzer: [
+        plt_file: {:no_warn, "priv/plts/dialyzer.plt"},
+        plt_add_deps: :app_tree,
+        plt_add_apps: [:mix, :plug]
+      ],
       docs: [extras: ["README.md"], main: "readme"]
     ]
   end