Merge pull request #22 from simmianand/feature/task-1564

Add a field to tag and attach file while creating the task #1564
Merge pull request #21 from simmianand/feature/task-1662

Attachments with duplicate name #1662
Fix migration typo
Convert commit handlers to classmethods
ModelView for get_gantt_data #1955

* This patch includes the __register__ method in a view model
  'TimesheetEmployeeDay' to create a relation for running get_gantt_data
  and get_comparison_data

Issue ID: 242002
Task ID: project-7/task-1955