Skip repository storage path valitaions on test environment

Storage path are not created until `TestEnv.init`, so we must skip
their validation on initialization.

config/initializers/6_validations.rb

@@ -13,13 +13,17 @@ def storage_validation_error(message)
   raise "#{message}. Please fix this in your gitlab.yml before starting GitLab."
 end
 
-storage_validation_error('No repository storage path defined') if Gitlab.config.repositories.storages.empty?
+def validate_storages
+  storage_validation_error('No repository storage path defined') if Gitlab.config.repositories.storages.empty?
 
-Gitlab.config.repositories.storages.each do |name, path|
+  Gitlab.config.repositories.storages.each do |name, path|
     storage_validation_error("\"#{name}\" is not a valid storage name") unless storage_name_valid?(name)
 
     parent_name, _parent_path = find_parent_path(name, path)
     if parent_name
       storage_validation_error("#{name} is a nested path of #{parent_name}. Nested paths are not supported for repository storages")
     end
+  end
 end
+
+validate_storages unless Rails.env.test?

spec/initializers/6_validations_spec.rb

 require 'spec_helper'
+require_relative '../../config/initializers/6_validations.rb'
 
 describe '6_validations', lib: true do
   before :all do
@@ -17,7 +18,7 @@ describe '6_validations', lib: true do
     end
 
     it 'passes through' do
-      expect { load_validations }.not_to raise_error
+      expect { validate_storages }.not_to raise_error
     end
   end
 
@@ -27,7 +28,7 @@ describe '6_validations', lib: true do
     end
 
     it 'throws an error' do
-      expect { load_validations }.to raise_error('"name with spaces" is not a valid storage name. Please fix this in your gitlab.yml before starting GitLab.')
+      expect { validate_storages }.to raise_error('"name with spaces" is not a valid storage name. Please fix this in your gitlab.yml before starting GitLab.')
     end
   end
 
@@ -37,7 +38,7 @@ describe '6_validations', lib: true do
     end
 
     it 'throws an error' do
-      expect { load_validations }.to raise_error('bar is a nested path of foo. Nested paths are not supported for repository storages. Please fix this in your gitlab.yml before starting GitLab.')
+      expect { validate_storages }.to raise_error('bar is a nested path of foo. Nested paths are not supported for repository storages. Please fix this in your gitlab.yml before starting GitLab.')
     end
   end
 
@@ -47,15 +48,11 @@ describe '6_validations', lib: true do
     end
 
     it 'passes through' do
-      expect { load_validations }.not_to raise_error
+      expect { validate_storages }.not_to raise_error
     end
   end
 
   def mock_storages(storages)
     allow(Gitlab.config.repositories).to receive(:storages).and_return(storages)
   end
-
-  def load_validations
-    load File.join(__dir__, '../../config/initializers/6_validations.rb')
-  end
 end