Cloud Fetch tests

[mattdeekay]

Unit and end-to-end tests:

• batchloader_test.go (unit)
  • test cloud fetch happy case where the server returns arrow batch bytes
  • test cloud fetch sad case where the server status code is 500
• fetcher_test.go (unit)
  • test concurrent fetcher with mock fetchable items to check if results are expected and whether the fetcher took the estimated amount of time
• cloudfetch_test.go (e2e)
  • test end to end functionality of cloud fetch by comparing actual results from execution with and without cloud fetch