upgrade algebird, hit two nine three
Remove test_tutorials to see if everything else passed the examples
Add test_tutorials back and change 2.9.3 back to 2.9.2.
Change SBT version to 0.12.0 in scald.rb.
Merge pull request #506 from twitter/feature/upgrade_alg

Upgrade to Scala 2.9.3, bump Algebird