Added pre/post hooks for main build targets to allow projects to override pre/post functionality without needing to override the whole target
Added pre/post hooks for main build targets to allow projects to
override pre/post functionality without needing to override the whole
target

Joble/CumulusCI,motivislearning/CumulusCI,steelbrick/CumulusCI,e02d96ec16/CumulusCI,roundcorner-products/CumulusCI,jorrit-steporange/CumulusCI,jorrit-steporange/CumulusCI,roundcorner-products/CumulusCI,cdcarter/CumulusCI,ddrezga/CumulusCI,SalesforceFoundation/CumulusCI,ddrezga/CumulusCI,motivislearning/CumulusCI,SalesforceFoundation/CumulusCI,e02d96ec16/CumulusCI,steelbrick/CumulusCI