Examples cleanup

Created by: scarrazza

Issue by scarrazza Monday May 29, 2017 at 14:26 GMT Originally opened as https://github.com/NNPDF/validphys2/issues/6

---

In gitlab by @scarraza on Apr 4, 2017, 10:25

Simplify and reorganize examples folder as soon as we have NNPDF3.1.