* Update rails to version 5.1.1

* Run `rails app:update`

* Remove the override of polymorphic activity relationship

* Silence warning about otp_secret attribute being unknown to rails

* We will only introduce form_with where we want to use remote data

* Add inclusion validation for activity_type

* When excluding all types with `WHERE NOT IN`, the query search all rows.

* add annotate to Gemfile

* rails g annotate:install

* configure annotate_models

* add schema info to models

* fix rubocop to add frozen_string_literal

* Add exclude_types param to /api/v1/notifications

* Exclude notification types in web UI through exclude_types in the API

improved how "show more" link looks

Better initial state for unlisted/nsfw toggles