Swot-simulator

* Logging settings
* Plugins to interpolate Schism maps
* Fixes issues on Nadir products

* DATA folder is not available after pip install.
* Added a test set to interpolate an SSH.

* Bug fix: swaths are stored from right to left instead of left to right.
* Writing of Nadir products in proper format (official GDR reduced format).
* Addition of the orbital error.
* The simulator version is written in the generated products.

* Support for unsmoothed products.
* Retains the simulation parameters.
* Bug fix: cross track distances are written in km.
* Set the satellite coordinates at the equator.
* Refactor the plugin architecture.

* Restructuring of the random number generation.
* The long wavelengths are kept to simulate the low frequency signal.
* Added a method to get default settings.
* The signal is insufficient randomness at large wavelengths.
* Bug fix: The gyroscope effect is not considered.
* Adding the documentation.
* Added generation tests under Windows