manual tests for tester plugin should/can be removed

[gioman]

The manual tests can be safely removed as they covered scenarios are anyway checked in fully manual test cases in the BD test cycles.

[SrNetoChan]

@volaya I am more interested in going in the opposite direction. To replace manual tests in JIRA by semi-automated ones on the tester plugin. Especially the ones that allow us to skip some intermediate setting steps not entirely related to what we aim to test.