Changes to upgrading and getting lein-deb to work with clojure 1.5.1

1) Upgraded to using clojure/1.5.1, involed removing clojure.contrib deps
2) Added a sample.project.clj to illustrate a working example of lein-deb
3) Document
Merge pull request #1 from ystad/update-lein-deb

Changes to upgrading and getting lein-deb to work with clojure 1.5.1