add decrypt function and fix init load of temp data

[ankitforcode]

• fixes the initial load for the test data.
• adds decrypt block testing for transit backend.
• fix for the proper parameters as per the documentation.

[ankitforcode]

@tradel can you please review.

[tradel]

Declining to merge, as the setup/teardown issues are fixed by upgrading Locust to 0.9.0, and the --secrets option works fine without renaming.