Fixed the version of some dependencies

This bug was detected by SensioLabs Insight (rule # 32-079)
Refactored the Compressor class to remove long methods

This bug was detected by SensioLabs Insight (rule # 36-033):

  "PHP methods should not contain too much logic (i.e. less than 50 lines)"
Refactored the BookCustomizeCommand class to remove long methods

This bug was detected by SensioLabs Insight (rule # 36-033):

"PHP methods should not contain too much logic (i.e. less than 50 lines)"
Refactored the Validator class to remove long methods

This bug was detected by SensioLabs Insight (rule # 36-033):

"PHP methods should not contain too much logic (i.e. less than 50 lines)"