Remove scipy dependencies.

Was depending on scipy.optimize, brent and brentq function.
Replaced by secant method root finding and successive parabolic
interpolation local minimum finding.

Signed-off-by: Martin Raspaud <martin.raspaud@smhi.se>
Merge branch 'feature-no-scipy' into develop
Bump up version number.

Signed-off-by: Martin Raspaud <martin.raspaud@smhi.se>
Merge branch 'develop'