Added validations for Rehearsal

Added time zone around filter
Rehearsal start must be after AGMA contracted start
Rehearsal end must be before AGMA contracted end
Rehearsal Duration must be multiple of AGMA increments
Removed duplicate error messages for Start & End Time
Refactored Auth Macro
Added Company Class model

Added Company Class model
Consolidated Rehearsal & Company Class factories into Event Factory file
Added company class to Event#index

Fixed scope bug in Account spec - same thing tested in Associations
section
Fixed validation bug in Rehearsal/Company Class model if no AgmaProfile
found