v1.0.0

- Refactoring

- Simplified the usage of some features

- New features for saving, loading & updating "presets" (JSON files containing OSM and matplotlib parameter configurations)

- plot = prettymaps.plot() now outputs a "Plot" object contaning:

• geodataframes: a pandas dataframe with all the data fetched from OSM.
• ax: a matplotlib axis element; can now be used to update or add new matplotlib elements to prettymaps plot. Example plot.ax.set_title("Barcelona").
• fig: a matplotlib figure element; can now be used to update or add new matplotlib elements to prettymaps plot. Example plot.fig.patch.set_facecolor("#fff").

- Updated the examples.ipynb notebook

- Updated README with a short tutorial