Use describe on feature tests

The `type: :feature` is automatically detected by RSpec because these
tests are inside the `spec/features` folder. Using `feature` re-adds a
`type: :feature` to these files, which will result in a conflict when we
upgrade to Rails 5.1's system tests.

Because of this change, we also need to change `background` to `before`
or else these tests will fail.

spec/features/verification/email_spec.rb

@@ -1,6 +1,6 @@
 require "rails_helper"
 
-feature "Verify email" do
+describe "Verify email" do
 
   scenario "Verify" do
     user = create(:user,

spec/features/verification/letter_spec.rb

@@ -1,6 +1,6 @@
 require "rails_helper"
 
-feature "Verify Letter" do
+describe "Verify Letter" do
 
   scenario "Request a letter" do
     user = create(:user, residence_verified_at: Time.current,

spec/features/verification/level_three_verification_spec.rb

@@ -1,6 +1,6 @@
 require "rails_helper"
 
-feature "Level three verification" do
+describe "Level three verification" do
   scenario "Verification with residency and verified sms" do
     create(:geozone)
     user = create(:user)

spec/features/verification/level_two_verification_spec.rb

@@ -1,6 +1,6 @@
 require "rails_helper"
 
-feature "Level two verification" do
+describe "Level two verification" do
 
   scenario "Verification with residency and sms" do
     create(:geozone)

spec/features/verification/residence_spec.rb

@@ -1,8 +1,8 @@
 require "rails_helper"
 
-feature "Residence" do
+describe "Residence" do
 
-  background { create(:geozone) }
+  before { create(:geozone) }
 
   scenario "Verify resident" do
     user = create(:user)

spec/features/verification/sms_spec.rb

@@ -1,6 +1,6 @@
 require "rails_helper"
 
-feature "SMS Verification" do
+describe "SMS Verification" do
 
   scenario "Verify" do
     user = create(:user, residence_verified_at: Time.current)

spec/features/verification/verification_path_spec.rb

@@ -1,6 +1,6 @@
 require "rails_helper"
 
-feature "Verification path" do
+describe "Verification path" do
 
   scenario "User is an organization" do
     user = create(:user, verified_at: Time.current)

spec/features/verification/verified_user_spec.rb

@@ -1,6 +1,6 @@
 require "rails_helper"
 
-feature "Verified users" do
+describe "Verified users" do
 
   scenario "Verified emails" do
     user = create(:user,