fix strict standart warning
Merge branch '3.2.0' of https://github.com/OnApp/OnApp-PHP-Wrapper-External into 3.2.0

* '3.2.0' of https://github.com/OnApp/OnApp-PHP-Wrapper-External:
  fix strict standart warning
  Init OnApp_BillingPlan_ResourceHypervisorGroup
  add OnApp 3.2 compatibility
  add OnApp 3.2 compatibility