Update padds.py

[Jinadelee]

This will ensure new_value within the predefined min and max bounds

[coveralls]

Pull Request Test Coverage Report for Build 842

• 1 of 1 (100.0%) changed or added relevant line in 1 file are covered.
• 3 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.07%) to 89.941%

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Files with Coverage Reduction	New Missed Lines	%
spotpy/algorithms/rope.py	1	93.58%
spotpy/algorithms/sceua.py	2	88.79%

Totals
Change from base Build 836:	-0.07%
Covered Lines:	4131
Relevant Lines:	4593

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💛 - Coveralls

[thouska]

Hi @Jinadelee,
thanks for the contribution, this was indeed an error. Thx for the fix.
Please note that, you might face other unresolved errors in padds as it is in a early beta testing-phase in spotpy, so it is, different to the other implemented algorithms, currently not ready for production use. However, your valueable contribution brings us closer to the goal of having padds robustly implemented.