Add Fields::Array#push as an alias to #<<

lib/rackstash/fields/array.rb

@@ -85,6 +85,7 @@ module Rackstash
         @raw << normalize(value)
         self
       end
+      alias push <<
 
       # @return [::Array] deep-transforms the array into a plain Ruby Array
       def as_json(*)

spec/rackstash/fields/array_spec.rb

@@ -99,6 +99,12 @@ describe Rackstash::Fields::Array do
     it 'returns the array' do
       expect(array << 'value').to equal array
     end
+
+    it 'can use push as an alias' do
+      expect(array.push 'value').to equal array
+      expect(array[0]).to eql 'value'
+    end
+
   end
 
   describe '#as_json' do