Resolve "MWPotential2014 : Amplitude must have a unit"

This MR closes #906 (closed). I also updated the mass units of the second unit example to ensure the masses are also properly converted. Now, the two examples have the same with tiny deviations (see issue #906 (closed) for the plots).

added bug label

assigned to @matthieu

added 5 commits

• 78741832 - Add units conversion for the amplitude of the bulge
• 552ebf97 - Update MWpotential14 example units and amplitude
• d76fa8d7 - Update parameter_example.yml
• bccec9b5 - Update doc
• dcbb8958 - Apply format.sh

Compare with previous version

Thanks!

merged

mentioned in commit 002539c0