working with anisotropic data and non-integer voxel sizes

[davidackerman]

We are generally assuming isotropic voxel sizes, though i don't know if this will require that much to fix.

However, we are also using Coordinates which means that everything has to be in integers. We should move away from this.

[mzouink]

Currently, the input voxel size is defined by the model input voxel size
e.g., if the resolution of the input is [6.7,8,8] and the model is [8,8,8]
Flow will work assuming that the input resolution is [8,8,8]
Is it good enough, or do we need to rescale the isotropic dimension?