Add schema validation to measurements API.
first step to async processing of upload.

Multipart File upload is synchronous. Load of file into C* happens asynchronously
via the pipeline
wire in s3 and pipeline to measurements resource.
move functionality into the pipeline.
http POST seems to be working.
QUIET AMAZONAWS!
http POST returns 202 and doesn't 500 in pipeline.
file-upload example curl
upload with tests.
remove testing take 1
actually call insert-measurements.
Data! We have data upload from csv.
We can update devices from the csv upload.
Make parsing of timestamps from the file better(?).
Tidy up measurements.clj layout (no functional changes).
Re-enable s3 upload.
bump kixi.pipe version.
Skeleton impl of uploads.
add correct location hdr to csv upload response.
Add rudimentary status reporting on upload.

Basically a SUCCESS/FAILURE json doc you can download. This will
eventually become a report with more details.