Tests of `rouwenhorst` fails occasionally

[shizejin]

I found test error of rouwenhorst in build log of #489. There is no build error when I resubmit the exactly same commit for LQMarkov, and I guess this error is occasionally triggered by certain random values.

For example, the same error is triggered 7 times during 1000 runs.

[jstac]

Thanks @shizejin. It looks like tol should be increased to, say, 1e-10. Does that fix it?

[shizejin]

@jstac Yes It works, the error only occur 5 times for 100000 runs after I increase tol to be 1e-10.

[jstac]

I think that's good enough.