Fixed some offenses

* Added new gems.

* Fixed Posgresql index tables with `public`.

Added indexes test.

Added test not crash getting indexes.

* Updated rake and rubocop.

Ruby 2.4.0 unifies Fixnum and Bignum into Integer.

https://bugs.ruby-lang.org/issues/12005

Fix following deprecated warnings in Ruby 2.4.0-preview3.

- `warning: constant ::Fixnum is deprecated`
- `warning: constant ::Bignum is deprecated`

use existence of 'Rails::Application' as indicator of Rails App instead of 'Rails', as many Ruby applications are using railties such as generators outside Rails

* add(annotate_models_spec): test coverage
* change(annotate_models#get_foreign_key_info): elide auto-generated fk names

Closes #404.

* Correct 'comas' to 'commas' in README

* Provide :hide_default_column_types option to make hiding of default configurable

* Use `NO_DEFAULT_COL_TYPES` as default when the `hide_default_column_types` option is not provided

* add option to exclude STI subclasses from annotation

Fix configuration in rails README link

Annotate should reset the cached information about columns

fix so that the wrapper-opening does not gets duplicated

Fix bundle in windows platform.

Allow rake 11 in annotate.gemspec

Annotate on_delete/on_update foreign key constraints

Add unit tests for classified sort option

Allow classified sorting without an ID column

Fix fatal error when using `annotate` with ActiveRecord 4.1