changed _findOptimShapeParam to a bisection algorithm

[yamanatoo]

To fix a case where the optimization loops until it reaches max_steps which can be expensive depending on the problem.
This happens when cond changes between 2 values, one higher than cond_range=[1] and the other lower than cond_range=[0]. It is dependent on the given delta c = 0.01 and the problem.

The bisection algorithm solves this and makes the optimization faster anyway.

[kylebeggs]

Thanks for the PR, this is a big improvement over the naive implementation here. We just need to bump the version number and then we can merge this.