Refactoring VcrGzipSerializer to normalize new cassettes

[victor-torres]

With these changes, it would be easier to add new cassettes when adding new tests and making calls to HubStorage and Dash APIs.

For example, you can use a dummy Scrapy Cloud project and its deploy API Key to add a new test cassette as following:

HS_PROJECT_ID=<project id> HS_AUTH=<api key> AUTH=<api key> USER_AUTH=<api key> HS_ENDPOINT= DASH_ENDPOINT= py.test tests/client/test_collections.py::test_new_case

This will use the production servers with the provided credentials and will create a new cassette file at tests/client/cassettes/test_collections/test_new_case.gz.

From now on you can execute the test with just:

py.test tests/client/test_collections.py::test_new_case

[codecov]

Codecov Report

Merging #112 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #112   +/-   ##
=======================================
  Coverage   93.61%   93.61%           
=======================================
  Files          28       28           
  Lines        1895     1895           
=======================================
  Hits         1774     1774           
  Misses        121      121

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[vshlapakov]

@victor-torres That's a very neat idea. Sorry for taking so long to review it, I was continuously failing to allocate enough time to check it carefully and test locally as required. Could you take a quick look into the comments pls?

[victor-torres]

Thank you for your comments here, @vshlapakov. I'm just waiting for some time before jumping into this PR again.

[victor-torres]

@vshlapakov I've just updated the pull request.

Easy way to test the feature:

Rename some test case, for example, tests/client/test_collections.py::test_truncate to tests/client/test_collections.py::test_truncate_new.

Execute the test command specifying the environment variables (you can use any dummy Scrapy Cloud project):

HS_PROJECT_ID=<project id> HS_AUTH=<api key> AUTH=<api key> USER_AUTH=<api key> HS_ENDPOINT= DASH_ENDPOINT= py.test tests/client/test_collections.py::test_truncate_new

Check the new cassette file tests/client/cassetes/test_collections/test_truncate_new.gz with:

git status

[vshlapakov]

That's just awesome, thank you so much 👏