Bout-install

Fixed `sundials` url

- Added `PETSc` mirror URL with accompanying bugfix
- Docker build automatically after merge
- Fixed `netCDF` URL

- Fixed petsc-bug in config

- Added `use_preinstalled` to `install_options` keyword in config
- Allow preinstalled binaries
- Bug-fixes regarding reading boolean values from config

- Bugfix: Use `absolute` when parsing config-files from command line
- Corrected documentation
- Added keywords to `setup.py`

Initial release where all tests are passing