Update earthquakes example

[StefRe]

Update earthquakes example

• add cartopy as alternative to deprecated basemap
• prevent numpy warning "Passing (type, 1) or '1type' as a synonym of type is deprecated"
• while updating check-installation.py I also removed the check for urllib as it's now included in the standard python distribution

Using cartopy of course results in visually the same plot:

Also I updated the html file to again correspond to the rst file using the make file in the repo. This includes not only the current changes to README.rst but also older changes, e.g. #10 that were made to the rst file only (sorry for the additional changes due using the current version 0.17.1 of docutils instead of 0.12).

[rougier]

Many, many thanks for all these fixes.