Removed unused code
Added read methods to datastore classes
Added write methods to datastore classes
Switched to datastore read and write methods in first steps
Updated feature sampler to stop writing to local filesystem
Removed unused code
Updated create_steward() to stop writing to local filesystem
Modified functions.unzip() to use a temp directory
Updated package_opentrails_archive() to stop writing to working directory
Stopped writing messages JSON files to local filesystem
Fixed annoying Flask path slash
Stopped writing named_trails.csv and .valid files to local filesystem
Stopped saving uploaded zipfile to local filesystem in validate_upload()
Cleaned up one unneeded os.makedirs()
Eventually, stop testing random branches
Updated transformed_trailheads() to stop writing to working directory
Updated transform_trailheads() to stop writing to working directory
Updated upload_trailheads() to stop writing to working directory
Updated upload() to stop writing to working directory
Removed no-longer needed Datastore upload() and download() methods