Added a capacity to give factors to the composite values infiller

[Rlamboll]

Pull request

Please confirm that this pull request has done the following:

• Tests added
• Documentation added (where applicable)
• Example added (either to an existing notebook or as a new notebook, where applicable)
• Description in CHANGELOG.rst added

Adding to CHANGELOG.rst

Please add a single line in the changelog notes similar to one of the following:

- (`#XX <https://github.com/znicholls/silicone/pull/XX>`_) Added feature which does something
- (`#XX <https://github.com/znicholls/silicone/pull/XX>`_) Fixed bug identified in (`#YY <https://github.com/znicholls/silicone/issues/YY>`_)

[znicholls]

Is the idea that creating composite values either takes a list of things to add or you specify factors for every variable? Is the major use case for specifying factors subtraction or am I missing something?

[Rlamboll]

Is the idea that creating composite values either takes a list of things to add or you specify factors for every variable? Is the major use case for specifying factors subtraction or am I missing something?

1. You can actually mix {str: list} and {str: dict} elements, but I imagine when you are doing complicated things like str: dict you will do it as a different operation each time. The major use case is indeed subtraction, hence the name of the branch, but I thought people might want conversion factors or other things to be done here too.

As you can see I'm having a lot of trouble with the linter, which seems to break things completely when run locally (error: cannot format 05_Multiple_infillers.ipynb: 'charmap' codec can't encode characters in position 20537-20592: character maps to <undefined>, probably a windows encoding bug) and produces unhelpful (though clearly different) error messages on github

[znicholls]

Nice that's a really clever solution.

I'll format things now and see how I go. I'll turn off notebook formatting in the same PR.

[znicholls]

Nice @Rlamboll :D