By following the official github "mantra" [1] I had no issues:
$ svn co https://github.com/wikimedia/pywikibot-core testpwb
Perhaps there is something wrong with your specific setup? As to commits, there has been no new commit in the 2.0 branch since December [2]
Strainu
[1] https://help.github.com/articles/support-for-subversion-clients/ [2] https://github.com/wikimedia/pywikibot-core/commits/2.0