Adding unit tests for diagnostics_tsls.
Adding unit tests for diagnostics_tsls.

TaylorOshan/pysal,jlaura/pysal,chhao91/pysal,ljwolf/pysal_core,jlaura/pysal,chhao91/pysal,TaylorOshan/pysal,darribas/pysal,lixun910/pysal,schmidtc/pysal,ljwolf/pysal_core,sjsrey/pysal_core,badjr/pysal,weikang9009/pysal,nathania/pysal,badjr/pysal,TaylorOshan/pysal,sjsrey/pysal_core,pedrovma/pysal,dfolch/pysal,sjsrey/pysal,pastephens/pysal,ljwolf/pysal,hasecbinusr/pysal,jlaura/pysal,sjsrey/pysal_core,pysal/pysal,ljwolf/pysal,lanselin/pysal,lixun910/pysal,darribas/pysal,nathania/pysal,ljwolf/pysal_core,hasecbinusr/pysal,spreg-git/pysal,schmidtc/pysal,pastephens/pysal,pastephens/pysal,dfolch/pysal,spreg-git/pysal,ljwolf/pysal,hasecbinusr/pysal,lixun910/pysal