Add json formatter.

lib/lograge.rb

@@ -1,5 +1,6 @@
 require 'lograge/version'
 require 'lograge/formatters/cee'
+require 'lograge/formatters/json'
 require 'lograge/formatters/graylog2'
 require 'lograge/formatters/key_value'
 require 'lograge/formatters/l2met'
@@ -39,7 +40,7 @@ def self.custom_options(event)
   #  - An object that responds to call with an event argument and returns
   #    true iff the event should be ignored.
   #
-  # The action ignores are given to 'ignore_actions'. The callable ignores 
+  # The action ignores are given to 'ignore_actions'. The callable ignores
   # are given to 'ignore'.  Both methods can be called multiple times, which
   # just adds more ignore conditions to a list that is checked before logging.
 

lib/lograge/formatters/json.rb

@@ -0,0 +1,10 @@
+require 'json'
+module Lograge
+  module Formatters
+    class Json
+      def call(data)
+        ::JSON.dump(data)
+      end
+    end
+  end
+end

spec/formatters/json_spec.rb

@@ -0,0 +1,6 @@
+require 'spec_helper'
+require 'lograge'
+
+describe Lograge::Formatters::Json do
+  it { expect( subject.call({ custom: 'data' })).to eq('{"custom":"data"}') }
+end