Update dropbox.py
Update dropbox.py

Updated to use hour and minutes also in times - to make it possible to have multiple runs the same date. Can now close issue 369 and 354
cgourlay/tapiriik,mduggan/tapiriik,cgourlay/tapiriik,cpfair/tapiriik,campbellr/tapiriik,cpfair/tapiriik,campbellr/tapiriik,cgourlay/tapiriik,cgourlay/tapiriik,mduggan/tapiriik,mduggan/tapiriik,cpfair/tapiriik,campbellr/tapiriik,mduggan/tapiriik,cpfair/tapiriik,campbellr/tapiriik