Fixes in PolylineWalker

[th3w4y]

Scenario:

• when there is no cached Polyline we get a None back from the .get_alt()
• when altitude is 0 we get 0 from .get_alt

Issue:

• In polylineWalker I was checking if .get_alt() or uniform(min_alt, max_lat) that clearly fails when altitude is zero.

Fixes:

• will fallback to read the previous position of the bot in the alt 0 or None case
• set the speed in PolylineWalker and passthrough to StepWalker

Additional very Important Fixes:

• Polyline Walker should return False if final destination not reached (might have teleported in some follow workers)
• fixed cache validation.. (this was causing API quota reached)

[mention-bot]

@th3w4y, thanks for your PR! By analyzing the annotation information on this pull request, we identified @mjmadsen and @solderzzc to be potential reviewers

[mjmadsen]

@th3w4y Thank you.

[julienlavergne]

There is branch without any return statement.
10 meters is also a problem for me. There might be less than that between the last steps of the polyline. I would prefer we make sure we reached the final step of the polyline.

[th3w4y]

I corrected it..

[mjmadsen]

@th3w4y can you rebase? @solderzzc put some changes in to polyline_walker

[th3w4y]

@mjmadsen i rebased...

[julienlavergne]

With these changes, now the problem is that movements are chaotics just like the screenshot of @solderzzc .
So there is still something to fix :P.

[th3w4y]

@anakin5 check last commit I believe this was causing the whole thing... 8f7f22c

This should fix also the @solderzzc screenshot he attached #5132

[julienlavergne]

Yes looks better :)

[mjmadsen]

👍

We agree this is in a working state now? :)

[julienlavergne]

Yes, it is working fine