Maliput implementation of spline

[Agustin Alba Chicar]

Make a one-way road implementation in Maliput that uses a road that follows a spline.

Use ignition::math for the spline interpolation. We need to understand #109 first to implement it.

[Agustin Alba Chicar]

At the moment we got a hardcoded spline and a car moving over it. I'm using ignition::math::Splines code to interpolate and fit the curve to those points.

[Agustin Alba Chicar]

Solved the problem with the road rendering (due to OBJ generation and environment for Director) and other issues regarding the orientation and support for 'r' coordinate.

Here the control points have been created over the z=0 plane and using a spiral equation which linearly increases its radius 10 meters each 30 degrees. Samples are taken each 30 degrees and the interpolation is made with ignition::math::Spline.

[Agustin Alba Chicar]

This branch is tracking the current work done.

[Andrés Fortier]

Next step: create issue in ignition math repo for changes in spline API / implementation

[Andrés Fortier]

See #113

[Agustin Alba Chicar]

@andres_fortier do you agree in closing this issue? We are currently tracking more specific things regarding splines and the main goal of this one was obtained.

[Andrés Fortier]

Totally, gogogo!