Common: deprecate and remove CloudfrontLoader

[chuwy]

trafficstars

AWS is changing its Cloudfront format.

We are contacting you because your AWS account contains at least one CloudFront web distribution with logging enabled. Starting December 12, 2019, Amazon CloudFront is adding the following seven new fields to access logs:

• c-port – The port number of the request from the viewer. • time-to-first-byte – The number of seconds between receiving the request and writing the first byte of the response, as measured on the server. • x-edge-detailed-result-type – When the result type is an error, this field contains the specific type of error. • sc-content-type – The value of the HTTP Content-Type header of the response. • sc-content-len – The value of the HTTP Content-Length header of the response. • sc-range-start – When the response contains the HTTP Content-Range header, this field contains the range start value. • sc-range-end – When the response contains the HTTP Content-Range header, this field contains the range end value.

[alexanderdean]

Will this break existing Snowplow pipelines using the CloudFront collector, or will they continue to run okay?

[benjben]

Remove Absence of CollectorPayload (None) should be supported $e4 in EtlPipelineSpec.scala when this happens