[Blocked] remove hacky fix for "invert turn lane arrow orientation"

[kfarr]

Streetmix.net inverts turn lane orientation when displaying in the lane, see https://github.com/streetmix/streetmix/issues/683

Streetmix3D displays the "true" value according to the DB, but this results in confusion: https://twitter.com/SounderBruce/status/883431538385276932

Perhaps turn lane orientations should be inverted for now as a "hacky" fix so that people see in 3D what they expect from the 2D visual.

[kfarr]

The "hacky fix" is already implemented: https://github.com/kfarr/streetmix3d/blob/master/src/aframe-streetmix.js#L289

However removing the "hacky fix" will require resolution of https://github.com/streetmix/streetmix/issues/683 as referenced above. Keeping this ticket open for visibility.