Fix bug where files over 2 GB would not be saved in Geo tracking DB

If an LFS file were over 2 GB, Sidekiq would fail with a message such as:

```
2917923200 is out of range for ActiveRecord::ConnectionAdapters::PostgreSQL::OID::Integer with limit 4
```

To fix, increase the value in the database from a 4-byte integer to a 8-byte integer.

changelogs/unreleased-ee/sh-fix-geo-file-size.yml

+---
+title: Fix bug where files over 2 GB would not be saved in Geo tracking DB
+merge_request:
+author:

db/geo/migrate/20170526214010_convert_file_bytes_to_int64.rb

+class ConvertFileBytesToInt64 < ActiveRecord::Migration
+  def change
+    change_column :file_registry, :bytes, :integer, limit: 8
+  end
+end

db/geo/schema.rb

@@ -11,14 +11,15 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20170302005747) do
+ActiveRecord::Schema.define(version: 20170526214010) do
+
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
   create_table "file_registry", force: :cascade do |t|
     t.string "file_type", null: false
     t.integer "file_id", null: false
-    t.integer "bytes"
+    t.integer "bytes", limit: 8
     t.string "sha256"
     t.datetime "created_at", null: false
   end