Models
ActiveRecord and Models
Merge pull request #11 from Hantim/Models

Active Record
Added Request class
Added post parameter validation
Fix notes in Request class
Fix notes
Merge pull request #12 from danilms/RequestClass

Added Request class
Applying Active record model
tmp
Add book page with validation
Fix notes in validation
Fix notes
Merge pull request #17 from danilms/add_book

Add book
Validator and Constraints
Correction for PR
Rebase from master and push on github