preview: make tiles subdir and provide default for imagery_offset arg

[jreiberkyle]

Two fixes to make preview cli command run successfully:

1. provide default value of False for imagery_offset
2. create tiles subdir in example directories for download functions to populate with tiles

Closes #79

[drewbo]

Thanks @jreiberkyle; default looks good. Instead of adding the tiles directory, can we instead update the two download functions to not hardcode that and instead pass it as the folder parameter?

• https://github.com/developmentseed/label-maker/blob/master/label_maker/utils.py#L32
• https://github.com/developmentseed/label-maker/blob/master/label_maker/utils.py#L83

Happy to update if you're busy with something else

[jreiberkyle]

yeah @drewbo , that solution sounds great! Go ahead and make changes to this as you see fit.

[drewbo]

@jreiberkyle I made the updates at https://github.com/developmentseed/label-maker/tree/preview-offset-arg-79. I can merge from there, or push those same commits to your branch if you give me edit access to this PR.

[jreiberkyle]

@drewbo nice! I believe you have access to this PR already (the little checkbox next to "Allow edits from maintainers" is checked). Will that work or do you need write access to the branch on my fork?

[drewbo]

@jreiberkyle you were right and I already had access; I was trying to push to your branch with the wrong method so I was getting a permissions error (https vs. ssh)