Updated our training kata to use the 12/4 Lambda Binaries

[Raab, Donald]

The latest binary required no changes for the GS Collections solutions branch which is nice.

The following branch has the solutions written with the Java 8 Streams library changes.

https://github.com/goldmansachs/gs-collections-kata/commits/solutions-java8-jcf

You can view the diff changes here:

https://github.com/goldmansachs/gs-collections-kata/commit/9c344e12e3f502c9f9f2961135a6b095207f9d88

The biggest surprise that required me to change some code was the result of groupBy not returning a List anymore.  I had to wrap the result in a Bag to compare it to the expected results in the tests.

There was also a problem I had where I was trying to reuse a stream, which I know is no longer allowed.

Other than that it was mostly replace Mapper with Function, and replace functions with function in the package names.