Fix warnings

lib/json/ld/context.ex

@@ -305,7 +305,7 @@ defmodule JSON.LD.Context do
 
   # 16.1)
   defp do_create_container_definition(_, %{"@container" => container})
-        when not container in ~w[@list @set @index @language],
+        when container not in ~w[@list @set @index @language],
     do: raise JSON.LD.InvalidContainerMappingError,
           message: "#{inspect container} is not a valid container mapping; @container must be either @list, @set, @index, or @language"
   # 16.2)

lib/json/ld/encoder.ex

@@ -319,11 +319,11 @@ defmodule JSON.LD.Encoder do
   end
 
 
-  defp encode_json(value, opts \\ []) do
+  defp encode_json(value, opts) do
     Jason.encode(value, opts)
   end
 
-  defp encode_json!(value, opts \\ []) do
+  defp encode_json!(value, opts) do
     Jason.encode!(value, opts)
   end
 

lib/json/ld/expansion.ex

@@ -304,7 +304,7 @@ defmodule JSON.LD.Expansion do
       # 8)
       %{"@value" => value} ->
         with keys = Map.keys(result) do                       # 8.1)
-          if Enum.any?(keys, &(not &1 in ~w[@value @language @type @index])) ||
+          if Enum.any?(keys, &(&1 not in ~w[@value @language @type @index])) ||
              ("@language" in keys and "@type" in keys) do
             raise JSON.LD.InvalidValueObjectError,
               message: "value object with disallowed members"

mix.exs

@@ -30,7 +30,7 @@ defmodule JSON.LD.Mixfile do
       # ExCoveralls
       test_coverage: [tool: ExCoveralls],
       preferred_cli_env: [
-        "coveralls": :test,
+        coveralls: :test,
         "coveralls.detail": :test,
         "coveralls.post": :test,
         "coveralls.html": :test