Do not fail when coveralls fails to upload

* Basically all the builds have been red :'(

.travis.yml

@@ -19,7 +19,7 @@ script:
   - mix credo --strict
   - # skip dialyzer for elixir 1.4 and erlang 18 as it produces weird errors, see #69
   - if ! ([[ "$TRAVIS_ELIXIR_VERSION" == "1.4"* ]] && [[ "$TRAVIS_OTP_RELEASE" == "18"* ]]); then mix dialyzer --halt-exit-status; fi
-  - mix coveralls.travis
+  - mix safe_coveralls.travis
 after_script:
   - mix deps.get --only docs
   - MIX_ENV=docs mix inch.report

mix.exs

@@ -19,7 +19,7 @@ defmodule Benchee.Mixfile do
       preferred_cli_env: [
         "coveralls": :test, "coveralls.detail": :test,
         "coveralls.post": :test, "coveralls.html": :test,
-        "coveralls.travis": :test],
+        "coveralls.travis": :test, "safe_coveralls.travis": :test],
       dialyzer: [
         flags:
           [:unmatched_returns, :error_handling, :race_conditions, :underspecs]
@@ -33,7 +33,7 @@ defmodule Benchee.Mixfile do
     ]
   end
 
-  defp elixirc_paths(:test), do: ["lib", "test/support"]
+  defp elixirc_paths(:test), do: ["lib", "test/support", "mix"]
   defp elixirc_paths(_),     do: ["lib"]
 
   def application do

mix/tasks.ex

@@ -0,0 +1,18 @@
+defmodule Mix.Tasks.SafeCoveralls.Travis do
+  @moduledoc """
+  Provides an entry point for travis's script that's safe from upload
+  errors.
+  """
+  use Mix.Task
+
+  @preferred_cli_env :test
+  @shortdoc "A safe variant that doesn't crash on failed upload."
+
+  def run(args) do
+    try do
+      Mix.Tasks.Coveralls.do_run(args, [type: "travis"])
+    rescue
+      ExCoveralls.ReportUploadError -> IO.puts "Upload to coveralls failed."
+    end
+  end
+end