minor edit.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/tsdbi@508 edb9625f-4e0d-4859-8d74-9fd3b1da38cb
Added test for python version used by TSjson.

git-svn-id: svn://svn.r-forge.r-project.org/svnroot/tsdbi@509 edb9625f-4e0d-4859-8d74-9fd3b1da38cb