Add s3clone integration test

[mpacer]

As I was working on the fs cloning API handler, I realized that we didn't have an integration test for the s3 cloning API handler.

We will need to cleanup the files created by the the cloning APIs, because otherwise we'll create a new file with a new name with each POST request.

• Adds integration test for the POST handler (checks for the successful match between the published file (on s3), the cloned file (on disk) and the source content)
• Updates the names to be more specifically about s3 cloning.
• This also adds a cleanup to the integration tests & cleans up the side-effect notebooks.

[codecov[bot]]

Codecov Report

Merging #162 into master will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #162   +/-   ##
=======================================
  Coverage   81.15%   81.15%           
=======================================
  Files          10       10           
  Lines         467      467           
=======================================
  Hits          379      379           
  Misses         88       88

[codecov[bot]]

Codecov Report

Merging #162 into master will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #162   +/-   ##
=======================================
  Coverage   81.15%   81.15%           
=======================================
  Files          10       10           
  Lines         467      467           
=======================================
  Hits          379      379           
  Misses         88       88