Error on invalid time interval + time window combinations for AveragedTimeInterval

[sandreza]

For

 schedule = AveragedTimeInterval(a, window=b)

It must be the case that a > b. If a = b or a < b the end result will produce NaNs.

[glwagner]

julia> AveragedTimeInterval(1, window=2)
ERROR: ArgumentError: Averaging window 2 is greater than the output interval 1.
Stacktrace:
 [1] #AveragedTimeInterval#19
   @ ~/.julia/packages/Oceananigans/tqmFU/src/OutputWriters/windowed_time_average.jl:85 [inlined]
 [2] top-level scope
   @ REPL[6]:1
 [3] top-level scope
   @ ~/.julia/packages/CUDA/BbliS/src/initialization.jl:52