Fit parameters

Fitting parameters are saved as dictionary. These data will be passed to lmfit.
Up to this point I'd never grasped the concept of a named tuple, but after @tacaswell 's comment, I read through the [python docs] (https://docs.python.org/2/library/collections.html#namedtuple-factory-function-for-tuples-with-named-fields), as the suggestions of @tacaswell are inevitably correct.  Is this what you were talking about?

```python

from collections import namedtuple
Parameters = namedtuple('Parameters', ['use', 'min', 'max', 'value', 'option4',
                                       'option2', 'option3', 'option0',
                                       'option1'])
para_dict = {'coherent_sct_amplitude': Parameters(5.0, 7.0, 8.0, 6.0, 5.0, 5.0,
                                                  5.0, 5.0, 5.0),
             ...
}         
```