WIP scorers: F1 pairwise clustering metric implementation

``` python
 """BlaBlaBla

    Description

    This function does something.

    :param name: The name to use.
    :type name: str.
    :param state: Current state to be in.
    :type state: bool.
    :returns:  int -- the return code.
    :raises: AttributeError, KeyError

    """
```
This is the preffered way to write docstrings, so that sphinx can parse them later.