add keyword argument to specify points to fit baseline

[Munazza Alam]

Add keyword argument that allows users to specify points (minimum 2) in wavelength space where the baseline fit should intersect with the spectrum.

[Adam Ginsburg]

You can select data to fit using sp.baseline.selectregion. If you want to set the baseline directly, you can also do that by setting sp.baseline.basespec. Again, though, I'm not sure either of these are what you're asking for.

[Adam Ginsburg]

To be more specific, you could do something like: sp.baseline.selectregion(50,100,exclude=[51,99]) which is unfortunately a bit of a hokey way to do what you describe.

There needs to be a sp.baseline.fit method - I'll add that now.