Merge branch 'fograckspace' into 'master'

Add fog-rackspace microgem to support backups using rackspace provider

## What does this MR do?

Adds fog-rackspace gem to Gemfile.

## Why was this MR needed?

Because fog moved the rackspace provider to separate gem.

## What are the relevant issue numbers?

#19197

See merge request !4986

Gemfile

@@ -91,6 +91,7 @@ gem 'fog-core', '~> 1.40'
 gem 'fog-local', '~> 0.3'
 gem 'fog-google', '~> 0.3'
 gem 'fog-openstack', '~> 0.1'
+gem 'fog-rackspace', '~> 0.1.1'
 
 # for aws storage
 gem "unf", '~> 0.1.4'

Gemfile.lock

@@ -243,6 +243,11 @@ GEM
       fog-core (>= 1.39)
       fog-json (>= 1.0)
       ipaddress (>= 0.8)
+    fog-rackspace (0.1.1)
+      fog-core (>= 1.35)
+      fog-json (>= 1.0)
+      fog-xml (>= 0.1)
+      ipaddress (>= 0.8)
     fog-xml (0.1.2)
       fog-core
       nokogiri (~> 1.5, >= 1.5.11)
@@ -858,6 +863,7 @@ DEPENDENCIES
   fog-google (~> 0.3)
   fog-local (~> 0.3)
   fog-openstack (~> 0.1)
+  fog-rackspace (~> 0.1.1)
   font-awesome-rails (~> 4.6.1)
   foreman
   fuubar (~> 2.0.0)