Basic email verification done

Still need to add forms to confirmation page to allow resending and add
rate limiting.

drop_all.sql

@@ -3,8 +3,9 @@
  * ONLY RUN IN DEVELOPMENT!
  */
 drop table _sqlx_migrations cascade;
-drop collation case_insensitive;
 drop table entry cascade;
 drop table feed cascade;
 drop table users cascade;
+drop table user_email_verification_token cascade;
 drop type feed_type;
+drop collation case_insensitive;