Add model tags hash for alternate option of filter by tag
Fix the find_by_tags method, add test of this method
Finish the TagsHash spec
Refactoring of the hash cache model
Refactoring of the get_hashes method
Refactoring based on code reviews
Optimise code for clearence
Доработка поиска по тегам

* Выделил парсинг строки тегов в контроллер item_controller и переработал тесты
* При поиске по тегам заменил поиск с join на поиск по хешам
* уточнил версию pq-notify для корректной работы guard
add test to test relevance in Model
optimise tests and existing hashes finding
правка опечатки
Merge pull request #83 from netDalek/feature-9-alternate-option

Feature 9 tags search
update Gemfile&Gemfile.lock with better_errors, binding_of_caller, coveralls
remove binding_of_caller due to incompatability with ruby 2.0
Merge pull request #84 from monshq/update-Gemfile-and-lock

Update Gemfile & Gemfile.lock with better_errors, coveralls
update gems: authority, haml
Merge pull request #86 from monshq/update-gems

update gems: authority, haml