Remove explicit requires from lib/elasticsearch

lib/elasticsearch/git.rb

-require "elasticsearch/git/model"
-require "elasticsearch/git/repository"
-
 module Elasticsearch
   module Git
   end

lib/elasticsearch/git/encoder_helper.rb

-require 'active_support/concern'
-require 'charlock_holmes'
-
 module Elasticsearch
   module Git
     module EncoderHelper

lib/elasticsearch/git/lite_blob.rb

-require 'linguist'
-require 'elasticsearch/git/encoder_helper'
-
 module Elasticsearch
   module Git
     class LiteBlob

lib/elasticsearch/git/model.rb

-require 'active_support/concern'
-require 'active_model'
-require 'elasticsearch/model'
-
 module Elasticsearch
   module Git
     module Model

lib/elasticsearch/git/repository.rb

-require 'active_support/concern'
-require 'active_model'
-require 'elasticsearch'
-require 'elasticsearch/git/model'
-require 'elasticsearch/git/encoder_helper'
-require 'elasticsearch/git/lite_blob'
-require 'rugged'
-require 'open3'
-
 module Elasticsearch
   module Git
     module Repository