testGtsamPose3SLAMExampleChordal takes too long for day-to-day testing

[dabrahams]

26 seconds really slows down the edit/test/debug cycle. If we need to run a test this big I suggest checking for a special command line argument and only running it when passed, or something.

[ProfFan]

@dabrahams I think we could try reducing the number of iterations and find a lowest number of iters to make it converge

[dabrahams]

If we make it deterministic by using only PRNGs, mightn't it be enough to check that the error follows some prescribed pattern for the first N iterations, rather than testing it all the way to convergence?

[ProfFan]

Yeah I agree, I can put this on my TODO :)