Merge pull request #314 from Nurhashimah/master

Misc fixes on PDF - kewpa 17, kewpa 19 & kewpa 20
Merge pull request #315 from Nurhashimah/master

Travel Request - Pdf format added + current_user fixed for vehicle part
misc fixes - Travel Request : mileage history added, fixed: approve button should not appear in (i)applicant show pg & (ii)when NOT YET submitted [replace_by & hod_id not exist]
travel request - model - required data setting for mileage history