fix: Fixed end-to-end script

[frgfm]

Following up on #134, this PR introduces the following modifications:

• fixes the payload for the device entry
• added proper DB cleanup at the end of the script

Any feedback is welcome!

[codecov]

Codecov Report

Merging #135 (b6c3c7f) into master (1c99e4e) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #135   +/-   ##
=======================================
  Coverage   88.47%   88.47%           
=======================================
  Files          27       27           
  Lines         807      807           
=======================================
  Hits          714      714           
  Misses         93       93           

Flag	Coverage Δ
unittests	88.47% <ø> (ø)

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