Add "why do you want to join" field to invite requests (#10524)

* Add "why do you want to join" field to invite requests

Fix #10512

* Remove unused translations

* Fix broken registrations when no invite request text is submitted

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2019_03_17_135723) do
+ActiveRecord::Schema.define(version: 2019_04_09_054914) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -679,6 +679,14 @@ ActiveRecord::Schema.define(version: 2019_03_17_135723) do
     t.index ["uri"], name: "index_tombstones_on_uri"
   end
 
+  create_table "user_invite_requests", force: :cascade do |t|
+    t.bigint "user_id"
+    t.text "text"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["user_id"], name: "index_user_invite_requests_on_user_id"
+  end
+
   create_table "users", force: :cascade do |t|
     t.string "email", default: "", null: false
     t.datetime "created_at", null: false
@@ -816,6 +824,7 @@ ActiveRecord::Schema.define(version: 2019_03_17_135723) do
   add_foreign_key "stream_entries", "accounts", name: "fk_5659b17554", on_delete: :cascade
   add_foreign_key "subscriptions", "accounts", name: "fk_9847d1cbb5", on_delete: :cascade
   add_foreign_key "tombstones", "accounts", on_delete: :cascade
+  add_foreign_key "user_invite_requests", "users", on_delete: :cascade
   add_foreign_key "users", "accounts", name: "fk_50500f500d", on_delete: :cascade
   add_foreign_key "users", "invites", on_delete: :nullify
   add_foreign_key "users", "oauth_applications", column: "created_by_application_id", on_delete: :nullify