fix: creating `Tasks` with `import` statements

[bednar]

Closes #490

Proposed Changes

Fixed creating Task with import statement:

task_flux = 'import "http"\n\n' \
            'from(bucket: "iot_center")\n' \
            '    |> range(start: -30d)\n' \
            '    |> filter(fn: (r) => r._measurement == "environment")\n' \
            '    |> aggregateWindow(every: 1h, fn: mean)'
task = self.tasks_api.create_task_cron("my-name", task_flux, "10 0 * * * *", self.organization.id)

Checklist

• [x] CHANGELOG.md updated
• [x] Rebased/mergeable
• [x] A test has been added if appropriate
• [x] pytest tests completes successfully
• [x] Commit messages are conventional
• [x] Sign CLA (if not already signed)

[codecov-commenter]

Codecov Report

Merging #491 (b5b6e44) into master (aa0f9a5) will not change coverage. The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #491   +/-   ##
=======================================
  Coverage   90.52%   90.52%           
=======================================
  Files          39       39           
  Lines        3355     3355           
=======================================
  Hits         3037     3037           
  Misses        318      318           

Impacted Files	Coverage Δ
influxdb_client/client/tasks_api.py	92.39% <100.00%> (ø)

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[bednar]

The task option is now appended at the end of script. @rhajek, @powersj can you review the changes again?