Multiple File Upload

[danielc2013]

Background
Currently, crossing-go allows for uploading a single KMS encrypted file. It would be advantageous to pull more than one

ToDo:
Take multiple files as an argument to crossing-go put and upload them to S3. The command would look like the following:
`crossing-go put -k alias/crossing-go-key <local_file> <s3_destination> <local_file> <s3_destination>

Definition of Done:

• crossing-go can put multiple files to S3
• Each file provided, can be put to a different endpoint

[thegonch]

So the idea would be that you could pass any number of <local_file> <s3_destination> combinations, as something like a comma separated list or something similar? I think a separator of some kind or some other format might be needed to make it both easier to parse and for the end user to write.

[jeffb4]

standard unix util syntax would be varargs with the last arg being the destination (which keeps with the cp-like syntax already in use)