Upgrade to Scala 2.10.

Seeing this error in the tests:

```
[error] /Users/sritchie/code/twitter/algebird/src/test/scala/com/twitter/algebird/BloomFilterTest.scala:59: Cannot construct a collection of type scala.collection.AbstractSeq[Int] with elements of type Int based on a collection of type scala.collection.AbstractSeq[Int].
[error]               val entries = RAND.shuffle(0 until 1000).take(numEntries + 1).map(_.toString)
```