Rename the spec root description

spec/s3/app_spec.rb

@@ -1,6 +1,6 @@
 require_relative "../spec_helper"
 
-describe "App" do
+describe "S3 provider" do
   def container_url_for(user)
     "#{app.settings.s3["endpoint"]}#{app.settings.s3["bucket"]}/#{user}"
   end

spec/swift/app_spec.rb

@@ -1,6 +1,6 @@
 require_relative "../spec_helper"
 
-describe "App" do
+describe "Swift provider" do
   def container_url_for(user)
     "#{app.settings.swift["host"]}/rs:documents:test/#{user}"
   end