Change order of parameters to be more pipe friendly

[CoffiDev]

I believe that the functionfrom_seconds(atom, seconds) and to_seconds(atom, multiplier) from the module Convert should have the parameters in the opposite order, because is more likely to pipe the value of the seconds through a pipe than the value of the atom.

Example:

Convert.from_seconds(:hours, foo())

foo() |> Convert.from_seconds(:hours)