Update rtax to 0.984
fixing issue 1089 principal_cordinates.py failing if the input folder contains other folders
Update test expectation to match correct rtax 0.984 output
remove obsolete comment re test failures
Merge pull request #1176 from teravest/issue1089

fixing issue 1089 principal_cordinates.py failing if the input folder co...
Merge pull request #1175 from davidsoergel/master

Update rtax to 0.984