Update to version 1.1

1.1 (2019-12-15)

- Symmetrize system
    - Scale the equations to match
    - Introduce subfunctionals
    - Subfunctionals are equal for off-diagonal entries
    - Resolve stf-terms using orthogonality
    - Make r13 as default in formulation rather than decoupled
    - Refactor CIP as separate subfunctionals
    - Add antisymm ring, not used for now but can improve convergence
- Create package
    - Move files into separate folder and add setup.py
    - CI is changed
    - Installation through "pip install ." in toplevel
- Clean repository