[SPECS] Guard dependency added.

== Addons

* 'guard-rspec' dependency.
* Guardfile
[FEATURE] Service##transaction changed to ##escape.

The ##transaction method is extracted to the 'hexx-active_record' gem.
Instead the ##escape method added to resque from block by publishing the :error notification.

== Deletions

* Hexx::Service##transaction.
* Hexx::Service::Transactions.

== Addons

* Hexx::Service::Escapes.
* Hexx::Service##escape.
[REFACTORING] Order of loading has been refactored.

Inner dependencies were extracted to lib/hexx.rb
[FEATURE] Service##run_service method has been added.

The method initializes and runs another service object and subscribes self for its notifications.

== Addons

* Service##run_service.
[REFACTORING] Service object has been refactored.

== Deletions

* Hexx::Service::Callbacks
* Hexx::Service::Escapes
* Hexx::Service::Messages
* Hexx::Service::Validations

All content from that modules has been moved to the Hexx::Service class.

== Changes

* Hexx::Service.

== Addons

YARD documentation added.
* .yardopts settings added.
* Documentation updated in a YARD-style
[VERSION] Changed to 3.0.0

Backward incompatible because of Service#transaction method's removal.