Implement /recommend. Move from RecommendResponse to generic IDValue. Use Response.Status instead of status codes. Slightly expand RecommendTest
Updates from Kam's review
Merge pull request #41 from srowen/master

Implement /recommend. Move from RecommendResponse to generic IDValue. Us...
Make more realistic model for writing tests
Tomcat 8.0.12
Support /recommend considerKnownItems and expand tests
Add JVM memory methods, rename Before/After methods to be less conflicting
Add load test, and change known-items data structure to something more compact