Bump dev version.
Regen docs.
Try to fix travis build.
Try to fix travis build.
Travis yml fix.
Travis fix.
Travis fix.
Print date of base image.

Base image date wasn't filling in case of cloud fill not being performed due to threshold.
Fix max_iter bug.
Add function to plot browse images.
Remove box and legend.
Move plotprep outside browse image function.
Fix bug in setting origin to 0,0.
Ensure output datatype is correctly set.
Bugfix for when some fill layers have no avail. fill pixels.

Also remove deprecated n_cpus argument.
One more bug fix for unavailable fill pixels.
Bump version.
Bump dev version.
Add a function to subsample pixel data.
Move to dplyr for efficiency.

Also refine sampling in pixel_data subsample method.