Updated Travis CI integration to test against multiple versions of Go
Added button to tick sites finished count in FleetDetails
go fmt + go vet + golint
Added additional payout officer access mask
Fixed implementation of (precise) HasAccessMask and added template function for HasHigherAccessMask
Replaced all checks for Admin-access mask with check for AccessMask higher PaymentOfficer
Added footer with copyright/legal notice
Added additional CSS for the footer
Added legal page with copyright notice and a few contact details
Reduced bottom margin to avoid scrollbar on static pages