Loosen requirement on request_store version

This gem follows semantic versioning and will not introduce breaking
changes in a minor version. See
https://github.com/steveklabnik/request_store#semantic-versioning

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/2868

Gemfile

@@ -225,7 +225,7 @@ gem 'gon',                '~> 6.1.0'
 gem 'jquery-atwho-rails', '~> 1.3.2'
 gem 'jquery-rails',       '~> 4.1.0'
 gem 'jquery-ui-rails',    '~> 5.0.0'
-gem 'request_store',      '~> 1.3.0'
+gem 'request_store',      '~> 1.3'
 gem 'select2-rails',      '~> 3.5.9'
 gem 'virtus',             '~> 1.0.1'
 gem 'net-ssh',            '~> 3.0.1'

Gemfile.lock

@@ -937,7 +937,7 @@ DEPENDENCIES
   redis (~> 3.2)
   redis-namespace (~> 1.5.2)
   redis-rails (~> 4.0.0)
-  request_store (~> 1.3.0)
+  request_store (~> 1.3)
   rerun (~> 0.11.0)
   responders (~> 2.0)
   rouge (~> 2.0)